NEW YORK (Standard&Poor's) Sept. 20, 2001--Standard&Poor's today affirmed its triple-'A' corporate credit and senior unsecured debt ratings as well as its 'A-1'-plus short-term corporate credit and commercial paper ratings on Bristol-Myers Squibb Co. The outlook remains negative. New York City-based Bristol-Myers Squibb Co. has announced that it has entered into an agreement with biotech firm, ImClone Systems, to codevelop and copromote ImClone's promising cancer treatment, IMC-C225. Under the agreement, Bristol-Myers will commit upwards of $1 billion in funding, based on certain milestones, for the development of IMC-C225, as well as acquire roughly 20% of ImClone for $1 billion. The deal is the latest in a series of recent strategic moves by Bristol-Myers to increase its focus