Common use of Authority and Authorization Clause in Contracts

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, the Registration Statement, the Pricing Disclosure Package and the Prospectus. At the applicable Closing Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Entities or any of their stockholders, partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite partnership power and authority to issue, sell and deliver the those Units to be issued, sold and delivered by it hereunderthe Partnership, in accordance with and upon the terms and conditions set forth in this Agreement, Agreement in accordance with and upon the terms and conditions set forth in the Partnership Agreement, the Registration Statement, the Pricing Disclosure Package and the Prospectus. At the applicable Closing DateTime and at each Date of Delivery, all corporate, partnership and limited liability company actionactions, as the case may be, required to be taken by the MarkWest Partnership Entities or any of their stockholderssecurityholders, members or partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall Agreement have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Primary Units to be sold by it hereunder, in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, the Registration Statement, the Pricing Disclosure Package and the Prospectus. At the applicable Closing Dateeach Settlement Date and each Time of Delivery hereunder, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Entities or any of their stockholders, partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, hereunder in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, Agreement and the Registration Statement, the Pricing Disclosure Package Statement and the Prospectus. At the applicable Closing Date and the Option Closing Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Inergy Entities or any of their stockholders, members or partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, hereunder in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, the Registration Statement, the Pricing Disclosure Package and the Final Prospectus. At the applicable Closing each Delivery Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Inergy Entities or any of their stockholders, members or partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, Agreement shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, hereunder in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, Agreement and the Registration Statement, the Pricing Disclosure Package Statement and the Prospectus. At the applicable Closing Date and the Option Closing Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Entities Inergy Parties or any of their stockholders, members or partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, the Registration Statement, the Pricing Disclosure Package and the Prospectus. At the applicable Closing Dateeach Settlement Date and each Time of Delivery hereunder, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Entities or any of their stockholders, partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, Agreement and the Registration StatementStatements, the Pricing Disclosure Package and the Prospectus. At the applicable Closing Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Entities or any of their stockholders, partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, Agreement and the Registration Statement, the Pricing Disclosure Package and the Prospectus. At the applicable Closing Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Entities or any of their stockholders, partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, hereunder in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, the Registration Statement, the Pricing Disclosure Package and the Prospectus. At the applicable Closing each Delivery Date and Option Delivery Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Inergy Entities or any of their stockholders, members or partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement and the Common Unit Purchase Agreement dated of even date herewith among the Partnership and each of the holders listed therein (the “Purchase Agreement”), shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, Agreement and the Registration Statement, the Pricing Disclosure Package Statement and the Prospectus. At the applicable Closing Date and the Option Closing Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Entities Parties or the Operating Subs or any of their stockholders, members or partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, hereunder in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, Agreement and the Registration Statement, the Pricing Disclosure Package Statement and the Prospectus. At the applicable Closing Date and the Option Closing Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Inergy Entities or any of their stockholders, members or partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, Agreement shall have been duly and validly taken.

Authority and Authorization. The Partnership has all requisite power and authority to issue, sell and deliver the Units to be sold by it hereunder, hereunder in accordance with and upon the terms and conditions set forth in this Agreement, the Partnership Agreement, the Registration Statement, the Pricing Disclosure Package and the Prospectus. At the applicable Closing each Delivery Date and Option Delivery Date, all corporate, partnership and limited liability company action, as the case may be, required to be taken by the MarkWest Inergy Entities or any of their stockholders, members or partners or members for the authorization, issuance, sale and delivery of the Units to be sold by the Partnership hereunder and the consummation of the transactions contemplated by this Agreement, Agreement shall have been duly and validly taken.