Redwood City-based Informatica Corporation said late Thursday that it is in a definitive agreement to acquire Nokia subsidiary Identity Systems, a provider of identity matching technology. Informatica say it will pay approximately $85M in cash for Identity Systems, in a deal that it expects to close by the end of May. Identity Systems develops technology for searching and matching information on individuals and organizations. The firm's software is used for cleaning, grouping, matching, and consolidating data in computer systems and databases. Identity Systems customers include the Internal Revenue Service, British Telecome, Experian, and others.