Exhibit 4 STOCK PURCHASE AGREEMENT STOCK PURCHASE AGREEMENT STOCK PURCHASE AGREEMENT (this "Agreement"), dated as of June 24, 2003, between Sewall Associates Family, L.P., a Delaware limited partnership ("Sewall"), and PMM GK Investment LLC, a...Stock Purchase Agreement • December 8th, 2003 • Montrone Paul M • Delaware
JOINT FILING AGREEMENTJoint Filing Agreement • December 8th, 2003 • Montrone Paul M
Pursuant to Rule 13d-1(k)(1)(iii) promulgated under the Securities Exchange Act of 1934, as amended, each of the undersigned agrees that the Statement on Schedule 13D, to which this exhibit is attached, is filed on its behalf.
