NEW YORK (Standard&Poor's CreditWire) April 25, 2001--Standard&Poor's today assigned its double-'B'-plus rating to Calpine Corp.'s $850 million convertible debentures (CARZ). In addition, Standard&Poor's affirmed all of its ratings on Calpine and its debt. The ratings include: Calpine's double-'B'-plus corporate credit rating, its double-'B'-plus rating on the company's $3.7 billion senior-unsecured debt, and its single-'B'-plus rating on Calpine's $1.12 billion convertible preferred securities and its double-'B'-plus rating on Calpine Canada's $1.5 billion of senior-unsecured debt. The outlook is stable. The issuance of the bonds will have a slightly negative effect on Calpine's credit profile. Calpine will use $717 million of the $850 million CARZ to refinance existing project finance debt at 10 of its generation