NEW YORK (Standard&Poor's CreditWire) Sept. 1, 1999--Standard&Poor's today affirmed Calpine Corp.'s double-'B' corporate credit rating and double-'B' rating on its senior unsecured notes. The outlook is stable. The affirmation follows Calpine's announcement of its agreement with Cogeneration Corp. of America (CGCA) to acquire 80% of CGCA's common stock for about $145 million. Calpine will also assume 80% of CGCA's $80 million in corporate debt and 80% of the $215 million in project debt. The total acquisition price is about $380 million, or about 17% of Calpine's existing capitalization of $2.2 billion. CGCA owns interests in six natural gas-fired facilities in the U.S. totaling approximately 580 megawatts (MW) of capacity. Standard&Poor's views the acquisition as