EXHIBIT A JOINT FILING AGREEMENT
EXHIBIT A
The undersigned hereby agree that the statement on Schedule 13D, Amendment No. 6, with respect
to the Common Stock of Sterling Chemicals, Inc. dated as of February 28, 2007 is, and any
amendments thereto (including amendments on Schedule 13G) signed by each of the undersigned shall
be, filed on behalf of each of us pursuant to and in accordance with the provisions of Rule
13d-1(k) under the Securities Exchange Act of 1934, as amended.
| Date: February 28, 2007 | RESURGENCE ASSET MANAGEMENT, L.L.C. | |||
| By: | /s/ XXXXXX X. XXXX | |||
| Name: | Xxxxxx X. Xxxx | |||
| Title: | Chairman and Chief Executive Officer | |||
| RESURGENCE ASSET MANAGEMENT, INTERNATIONAL L.L.C. | ||||
| By: | /s/ XXXXXX X. XXXX | |||
| Name: | Xxxxxx X. Xxxx | |||
| Title: | Chairman and Chief Executive Officer | |||
| RE/ENTERPRISE ASSET MANAGEMENT, L.L.C. | ||||
| By: | /s/ XXXXXX X. XXXX | |||
| Name: | Xxxxxx X. Xxxx | |||
| Title: | Chairman and Chief Executive Officer | |||
| XXXXXX X. XXXX | ||||
| /s/ XXXXXX X. XXXX | ||||
