MICROSOFT, IBM, AND Rational Software on Monday all declined comment on published reports last week that a second bidder, namely Microsoft, would put in a bid to acquire Rational. IBM on Dec. 6 agreed to acquire Rational Software for $2.1 billion. The acquisition is intended to enable IBM, in Armonk, N.Y., to provide a software development environment for companies to integrate business processes and software infrastructure across their operations, including suppliers and customers. Software Development