-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
UBS WARBURG
PRELIMINARY BACKGROUND INFORMATION
MASTR ALTERNATIVE LOAN TRUST SERIES 2002-3
------------------------------------------
DISCLAIMER
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
THIS PAGE MUST BE ACCOMPANIED BY A DISCLAIMER. IF YOU DID NOT
RECEIVE SUCH A DISCLAIMER, PLEASE CONTACT YOUR UBS WARBURG
FINANCIAL ADVISOR IMMEDIATELY.
--------------------------------------------------------------------------------
UBS WARBURG 1
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
PRICING INFORMATION
-----------------------------------------------------------------------------------------------------------------------------------
APPROXIMATE COUPON/ WAL PRINCIPAL WINDOW EXPECTED RATINGS
CLASS PRINCIPAL AMOUNT TRANCHE TYPE (YRS) CALL/MAT (4) (YEARS) CALL/MAT S&P / XXXXX'X
----- ----------------- ------------ --------------- ---------------- -------------
A-IO(1) $135,000,000 Scheduled Notional IO 2.01/2.01(5) NA AAA/Aaa
A-1(1,2) $211,600,000 Floating/Sequential 0.75/0.75 Dec02-Apr04/Dec02-Apr04 AAA/Aaa
A-2(1,2,3) $141,700,000 Fixed/Sequential 2.00/2.00 Apr04-Jul05/Apr04-Jul05 AAA/Aaa
A-3(1,2,3) $90,100,000 Fixed/Sequential 3.25/3.25 Jul05-Nov06/Jul05-Nov06 AAA/Aaa
A-4(1,2,3) $76,200,000 Fixed/Sequential 5.00/5.00 Nov06-Apr9/Nov06-Apr09 AAA/Aaa
A-5(1,2,3) $55,858,562 Fixed/Sequential 9.07/10.27 Apr09-Nov12/Apr09-Aug19 AAA/Aaa
A-6(1,2,3) $67,300,000 Fixed/Lockout 6.44/6.47 Dec05-Nov12/Dec05-Jun19 AAA/Aaa
-----------------------------------------------------------------------------------------------------------------------------------
(1) Subject to the Net WAC Cap as defined below.
(2) Subject to the Net Funds Cap as defined below.
(3) The coupon on the Class increases 50 bps after the clean-up call date.
(4) See "Pricing Prepayment Speed" below.
(5) Based on the Notional Balance
ANTICIPATED DESCRIPTION OF THE LOANS
--------------------------------------------------------
Current Balance: $673,751,114
Average Balance: $333,254
Minimum Balance: $30,400
Maximum Balance: $1,320,000
Wtd Average Gross Coupon: 7.708%
Wtd Average Original Term (months): 331
Wtd Average Seasoning (months): 4
Wtd Average Loan-To-Value Ratio: 75.7%
Fixed loans (% of Pool Principal Balance) 100%
--------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 2
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
DESCRIPTION OF SECURITIES
Pricing Prepayment
Speed: The Certificates were priced based on the following
prepayment assumptions: 100% PPC where 100% PPC is equal
to 6% - 25% CPR over 12 months and 25% CPR thereafter.
Distribution Date: The 25th day of each month (or the next succeeding business
day) commencing in December 2002.
Expected Settlement
Date: November 29, 2002
Accrued Interest: The price to be paid by investors for the Certificates,
with the exception of the Class A-1 Certificates, will
include accrued interest from the first of the month to the
settlement date. In the case of the Class A-1 Certificates,
accrued interest will be paid from November 25th to the
settlement date.
Interest Accrual
Period: With the exception of the Class A-1 Certificates, interest
will accrue on the Certificates at a fixed rate during the
month prior to the month of the related Distribution Date
based on a 30/360 basis. With respect to the Class A-1
Certificates, interest will accrue from and including the
preceding Distribution Date (or from and including November
25th in the case of the first Distribution Date) to and
including the day prior to the current Distribution Date at
the Class A-1 Certificate Interest Rate on an Actual/360
basis. With respect to any Distribution Date, the Class A-1
Certificate Interest Rate will be equal to the lesser of
(a) One Month LIBOR plus __% per annum and (b) Net Rate
Cap.
Payment Delay: With the exception of the Class A-1 Certificates, 24 days.
With respect to the Class A-1 Certificates, 0 days.
Issuer: MASTR Alternative Loan Trust 2002-3
Depositor: Mortgage Asset Securitization Transactions, Inc.
Master Servicer: Xxxxx Fargo Bank Minnesota, N.A.
Servicers: TBA
Transferor: UBS Warburg Real Estate Securities, Inc.
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 3
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
DESCRIPTION OF SECURITIES (CONTINUED)
Trustee: TBA
Servicer Advancing: The Servicers are required to make cash advances to cover
delinquent payments of principal and interest to the extent
deemed recoverable.
Optional
Termination: The terms of the transaction allow for a clean-up call (the
"Clean-up Call") which may be exercised once the current
aggregate principal balance of the Mortgage Loans is less
than or equal to 5% of the initial aggregate principal
balance of the Mortgage Loans.
Mortgage Loans: As of the Closing Date, it is anticipated that the
aggregate principal balance of the Mortgage Loans will be
approximately $673,751,114.
Net WAC Cap: The Class A-IO, A-1, A-2, A-3, A-4, A-5, A-6, M-1, M-2 and
B Certificates will be subject to a Net WAC Cap equal to
the weighted average of the net mortgage rates on the
Mortgage Loans.
Net Funds Cap: The Class A-1, A-2, A-3, A-4, A-5, A-6, M-1, M-2 and B
Certificates will be subject to a Net Funds Cap equal to
the (i) until the distribution date in November 2005, the
weighted average of the net mortgage rates on the Mortgage
Loans adjusted for the interest payable on the Class A-IO
Certificates and (ii) thereafter, the weighted average of
the net mortgage rates on the Mortgage Loans.
Basis Risk
Shortfall: The excess, if any, of the interest due Class A-1, A-2,
A-3, A-4, A-5, A-6, M-1, M-2 and B Certificates calculated
at the Net WAC Cap over the interest due such class
calculated at the Net Funds Cap plus any basis risk
shortfall remaining unpaid from prior distribution dates on
such class plus interest on such amount at the Net Funds
Cap rate.
Credit Enhancement: Credit enhancement for the Certificates will consist of (i)
Excess Interest, (ii) Overcollateralization and (iii)
subordination provided to the more senior classes of
certificates by the more subordinate classes of
certificates.
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 4
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
DESCRIPTION OF SECURITIES (CONTINUED)
Excess Interest: The interest collections from the Mortgage Loans less the
sum of (i) the interest paid on the Certificates; and (ii)
the aggregate of all fees and payments due in respect of
the Mortgage Loans.
Over-
collateralization The Certificateholders will be entitled to receive
distributions of Excess Interest as principal until the
Overcollateralization Amount equals the Required
Overcollateralization Amount. This distribution of interest
as principal will have the effect of accelerating the
Certificates relative to the underlying Mortgage Loans. On
any Distribution Date, the Overcollateralization Amount
will be the amount, if any, by which the Mortgage Loan
balance exceeds the Aggregate Principal Balance of the
Certificates.
Subordination The rights of the holders of the Class A Certificates to
receive distributions will be senior to the rights of the
Mezzanine Certificates and the Subordinate certificates.
Similarly, the rights of the holders of the Mezzanine
Certificates with higher payment priorities will be senior
to the rights of the Mezzanine Certificates with lower
payment priorities and the Subordinate Certificates.
Stepdown Date: Shall be the later to occur of (a) the Distribution Date in
December 2005, and (b) the first Distribution Date on which
the aggregate principal balance of the Senior Certificates
is less than or equal to [ ]% of the aggregate principal
balance of the Mortgage Loans for such Distribution Date,
if 100% of principal collections had been distributed.
Class A-IO Interest
Amount For each distribution date, product of [ ]% per annum and
the notional balance of the Class A-IO for that
distribution date, however, for the first [ ] months, [ ]
of the interest amount otherwise calculated will instead be
made available for distribution as Remaining Funds (defined
below) beginning with distribution priority (2)
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 5
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
Class A-IO
Notional Amount For each distribution date, the notional balance of the
Class A-IO will be the lesser of the aggregate loan balance
and:
--------------------------------------------
Up to and including $135,000,000
5/25/03
--------------------------------------------
From 6/25/03 to and $120,000,000
including 11/25/03
--------------------------------------------
From 12/25/03 to and $100,000,000
including 5/25/04
--------------------------------------------
From 6/25/04 to and $85,000,000
including 11/25/04
--------------------------------------------
From 12/25/04 to and $65,000,000
including 5/25/05
--------------------------------------------
From 6/25/05 to and $40,000,000
including 11/25/05
--------------------------------------------
Thereafter $0
--------------------------------------------
Class A-6
Priority Amount For each distribution date, the Class A-6 Priority Amount
is equal to the product of (i) Class A-6 percentage (ii)
Class A-6 Lockout Distribution Percentage and (iii) the
available Senior Certificate principal amount.
Class A-6
Percentage For each distribution date, the percentage will equal to
Class A-6 principal balance immediately prior to such
distribution date divided by the sum of the aggregate
Senior Certificate principal balances.
Class A-6 Lockout Distribution Percentage
--------------------------
From To Percent
Month Month
--------------------------
0 36 0%
--------------------------
37 60 45%
--------------------------
61 72 80%
--------------------------
73 84 100%
--------------------------
85 End 300%
--------------------------
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 6
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
DESCRIPTION OF SECURITIES (CONTINUED)
Priority of
Distributions: Available funds will be distributed in the following order
of priority:
INTEREST:
1) To pay interest to the Class A-IO
2) To pay unpaid interest shortfalls to the Class A-IO
3) Concurrently, to pay interest on the Class A-1
through A-6 Certificates
4) Concurrently, to pay unpaid interest shortfalls on
the Class A-1 through A-6 Certificates
5) To pay interest to the Class M-1
6) To pay unpaid interest shortfalls to the Class M-1
7) To pay interest to the Class M-2
8) To pay unpaid interest shortfalls to the Class M-2
9) To pay interest to the Class B
10) To pay unpaid interest shortfalls to the Class B
PRINCIPAL:
Generally, on each distribution date prior to the Stepdown
Date or on which a trigger event has occurred, the
principal payment amount will be paid in the following
order of priority:
1) To the Class A-6 the Class A-6 Priority Amount
2) To the Class A-1 through A-6 sequentially to zero
3) To the Class M-1 to zero
4) To the Class M-2 to zero
5) To the Class B to zero
Generally, on each distribution date on or after the
Stepdown Date and on which a trigger event has not
occurred, the principal payment amount will be paid in the
following order of priority:
1) To the Class A-6 the Class A-6 Priority Amount from
the senior principal payment amount
2) To the Class A-1 through A-6 sequentially to zero from
the remaining senior principal payment amount
3) To the Class M-1 to zero the Class M-1 principal
payment amount
4) To the Class M-2 to zero the Class M-2 principal
payment amount
5) To the Class B to zero the Class B principal payment
amount
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 7
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
REMAINING FUNDS
1) On each distribution date prior to the Stepdown Date or on which a
trigger event has occurred, until the aggregate class principal
balance of the certificates equals the aggregate loan balance for
such distribution date minus the targeted overcollateralization
amount for such date:
a) To the Class A-6 the Class A-6 priority amount
b) To the Class A-1 through A-6 sequentially to zero
c) To the Class M-1 to zero
d) To the Class M-2 to zero
e) To the Class B to zero
On each distribution date on or after the Stepdown Date and on which
a trigger event has not occurred, until the aggregate Class
Principal Balance of the certificates equals the aggregate Loan
Balance for such distribution date minus the targeted
overcollateralization amount for such date:
a) To the Class A-6 the Class A-6 priority amount
b) To the Class A-1 through A-6 sequentially to zero the
senior principal payment amount
c) To the Class M-1 to zero the Class M-1 principal payment
amount
d) To the Class M-2 to zero the Class M-2 principal payment
amount
e) To the Class B to zero the Class B principal payment
amount
2) To the Class M-1 any deferred amount for such class
3) To the Class M-2 any deferred amount for such class
4) To the Class B any deferred amount for such class
5) Concurrently, to the Class A Certificates, any Basis Risk Shortfall
for such class
6) To the Class M-1 Certificates, any Basis Risk Shortfall for such
class
7) To the Class M-2 Certificates, any Basis Risk Shortfall for such
class
8) To the Class B Certificates, any Basis Risk Shortfall for such class
9) To the Class X
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 8
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
WHOLE LOAN ALT-A FIXED-RATE
TOTAL
-----
GWAC 7.708% +/- 10BPS
WAM 327 +/- 2 MONTHS
30 YEAR 83.5% APPROX
15 YEAR 9.0% APPROX
15/30 BALLOONS 7.5% APPROX
CALIFORNIA 42% APPROX
WA LTV 76% APPROX
WA LOAN SIZE (16% CONFORMING) $333K APPROX.
INVESTOR OCCUPANCY 12% APPROX
PRIMARY OCCUPANCY 86% APPROX
SECONDARY OCCUPANCY 2% APPROX
FULL DOC 16% APPROX.
LIMITED/STATED/REDUCED DOC 70% APPROX.
NO DOC 14% APPROX.
CASH-OUT REFI 29% APPROX.
LOANS WITH PREPAY PENALTY 12% APPROX.
SF/PUD 83% APPROX.
WA FICO 702 APPROX.
ALL NUMBERS APPROXIMATE.
ALL TRANCHES SUBJECT TO 5% SIZE VARIANCE.
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 9
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
TO MATURITY
----------------------------------------------------------------
Class A-IO 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 10.737 4.00 4.00 4.00 4.00 4.00
----------------------------------------------------------------
Average Life 2.01 2.01 2.01 2.01 2.01
----------------------------------------------------------------
Window NA-NA NA-NA NA-NA NA-NA NA-NA
----------------------------------------------------------------
----------------------------------------------------------------
Class A-1 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 1.59 1.59 1.59 1.59 1.59
----------------------------------------------------------------
Average Life 9.41 0.96 0.75 0.62 0.53
----------------------------------------------------------------
Window Dec02-May18 Dec02-Oct 24 Dec02-Apr04 Dec02-Jan04 Dec02-Nov03
----------------------------------------------------------------
----------------------------------------------------------------
Class A-2 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 3.65 3.57 3.54 3.51 3.48
----------------------------------------------------------------
Average Life 19.61 2.65 2.00 1.60 1.33
----------------------------------------------------------------
Window May18-Dec25 Oct04-Jun06 Apr04-Jul05 Jan04-Dec04 Nov03-Aug04
----------------------------------------------------------------
----------------------------------------------------------------
Class A-3 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 4.27 4.22 4.19 4.17 4.14
----------------------------------------------------------------
Average Life 24.71 4.50 3.25 2.49 2.05
----------------------------------------------------------------
Window Dec25-Feb29 Jun06-Jun08 Jul05-Nov06 Dec04-Oct05 Aug04-Apr05
----------------------------------------------------------------
----------------------------------------------------------------
Class A-4 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 4.89 4.86 4.83 4.81 4.78
----------------------------------------------------------------
Average Life 27.31 7.60 5.00 3.74 2.84
----------------------------------------------------------------
Window Feb29-Mar31 Jun08-May13 Nov06-Apr09 Oct05-Jul07 Apr05-Jun06
----------------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 10
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
----------------------------------------------------------------
Class A-5 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 6.01 6.02 6.02 6.01 5.95
----------------------------------------------------------------
Average Life 29.01 13.98 10.27 7.12 4.78
----------------------------------------------------------------
Window Mar31-Jul32 May13-Jul24 Apr09-Aug19 Jul07-May16 Jun06-Nov13
----------------------------------------------------------------
----------------------------------------------------------------
Class A-6 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 4.79 4.77 4.77 4.78 4.80
----------------------------------------------------------------
Average Life 13.73 6.95 6.47 6.17 5.96
----------------------------------------------------------------
Window Dec05-May32 Dec05-May24 Dec05-Jun19 Jan06-Mar16 Feb06-Sep13
----------------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 11
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
TO CALL
----------------------------------------------------------------
Class A-IO 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 10.737 4.00 4.00 4.00 4.00 4.00
----------------------------------------------------------------
Average Life 2.01 2.01 2.01 2.01 2.01
----------------------------------------------------------------
Window NA-NA NA-NA NA-NA NA-NA NA-NA
----------------------------------------------------------------
----------------------------------------------------------------
Class A-1 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 1.59 1.59 1.59 1.59 1.59
----------------------------------------------------------------
Average Life 9.41 0.96 0.75 0.62 0.53
----------------------------------------------------------------
Window Dec02-May18 Dec02-Oct 24 Dec02-Apr04 Dec02-Jan04 Dec02-Nov03
----------------------------------------------------------------
----------------------------------------------------------------
Class A-2 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 3.65 3.57 3.54 3.51 3.48
----------------------------------------------------------------
Average Life 19.61 2.65 2.00 1.60 1.33
----------------------------------------------------------------
Window May18-Dec25 Oct04-Jun06 Apr04-Jul05 Jan04-Dec04 Nov03-Aug04
----------------------------------------------------------------
----------------------------------------------------------------
Class A-3 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 4.27 4.22 4.19 4.17 4.14
----------------------------------------------------------------
Average Life 24.71 4.50 3.25 2.49 2.05
----------------------------------------------------------------
Window Dec25-Feb29 Jun06-Jun08 Jul05-Nov06 Dec04-Oct05 Aug04-Apr05
----------------------------------------------------------------
----------------------------------------------------------------
Class A-4 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 4.89 4.86 4.83 4.81 4.78
----------------------------------------------------------------
Average Life 27.31 7.60 5.00 3.74 2.84
----------------------------------------------------------------
Window Feb29-Mar31 Jun08-May13 Nov06-Apr09 Oct05-Jul07 Apr05-Jun06
----------------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 12
-----------------------------------------------------------
MASTR ALTERNATIVE LOAN TRUST
SERIES 2002-3
-----------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED BY THE DESCRIPTION OF THE
MORTGAGE LOANS CONTAINED IN THE PROSPECTUS SUPPLEMENT
--------------------------------------------------------------------------------
----------------------------------------------------------------
Class A-5 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 6.00 5.99 5.98 5.96 5.93
----------------------------------------------------------------
Average Life 28.84 12.53 9.07 6.26 4.57
----------------------------------------------------------------
Window Mar31-Nov31 May13-Feb16 Apr09-Nov12 Jul07-Sep10 Jun06-Apr09
----------------------------------------------------------------
----------------------------------------------------------------
Class A-6 0 PPC 75 PPC 100 PPC 125 PPC 150 PPC
----------------------------------------------------------------
Yield at 100 4.79 4.77 4.77 4.77 4.76
----------------------------------------------------------------
Average Life 13.73 6.95 6.44 6.03 5.46
----------------------------------------------------------------
Window Dec05-Nov31 Dec05-Feb16 Dec05-Nov12 Jan06-Sep10 Feb06-Apr09
----------------------------------------------------------------
--------------------------------------------------------------------------------
THE INFORMATION HEREIN HAS BEEN PROVIDED SOLELY BY UBS WARBURG LLC. NEITHER
THE ISSUER OF CERTIFICATES NOR ANY OF ITS AFFILIATES MAKES ANY REPRESENTATION
AS TO THE ACCURACY OR COMPLETENESS OF THE INFORMATION HEREIN. THE INFORMATION
HEREIN IS PRELIMINARY, AND WILL BE SUPERSEDED BY THE APPLICABLE PROSPECTUS
SUPPLEMENT AND BY ANY OTHER INFORMATION SUBSEQUENTLY FILED WITH THE SECURITIES
AND EXCHANGE COMMISSION. THE INFORMATION CONTAINED HEREIN WILL BE SUPERSEDED
BY THE DESCRIPTION OF THE MORTGAGE LOANS CONTAINED AND/OR INCORPORATED
BY REFERENCE IN THE PROSPECTUS SUPPLEMENT RELATING TO THE CERTIFICATES
AND SUPERSEDES ALL INFORMATION CONTAINED IN ANY COLLATERAL TERM SHEETS
RELATING TO THE MORTGAGE POOL PREVIOUSLY PROVIDED BY UBS WARBURG LLC.
--------------------------------------------------------------------------------
UBS WARBURG 13
