EX-99 2 bs2ex.txt ADDITIONAL EXHIBITS Exhibit 99.1 JOINT FILER INFORMATION Date of Event Requiring Statement: April 18, 2007 Issuer Name and Ticker or Trading Symbol: Celanese Corporation (CE) Designated Filer: Blackstone Management Associates (Cayman) IV L.P. Other Joint Filers: Blackstone Capital Partners (Cayman) IV L.P., Blackstone Family Investment Partnership (Cayman) IV-A L.P., Blackstone Capital Partners (Cayman) IV-A L.P., Blackstone Chemical Coinvest Partners (Cayman) L.P. Addresses: The principal business address of each of the Joint Filers above is c/o The Blackstone Group, 345 Park Avenue, New York, New York 10154 Signatures: Blackstone Capital Partners (Cayman) IV L.P. By: Blackstone Management Associates (Cayman) IV L.P., its general partner By: Blackstone LR Associates (Cayman) IV Ltd., its general partner By: /s/ Robert L. Friedman ---------------------- Name: Robert L. Friedman Title: Director Blackstone Family Investment Partnership (Cayman) IV-A L.P. By: Blackstone Management Associates (Cayman) IV L.P., its general partner By: Blackstone LR Associates (Cayman) IV Ltd., its general partner By: /s/ Robert L. Friedman ---------------------- Name: Robert L. Friedman Title: Director
Blackstone Capital Partners (Cayman) IV-A L.P. By: Blackstone Management Associates (Cayman) IV L.P., its general partner By: Blackstone LR Associates (Cayman) IV Ltd., its general partner By: /s/ Robert L. Friedman ---------------------- Name: Robert L. Friedman Title: Director Blackstone Chemical Coinvest Partners (Cayman) L.P. By: Blackstone Management Associates (Cayman) IV L.P., its general partner By: Blackstone LR Associates (Cayman) IV Ltd., its general partner By: /s/ Robert L. Friedman ---------------------- Name: Robert L. Friedman Title: Director