SAN FRANCISCO — Attorneys at Palo Alto-based Feinberg Day Alberti & Thompson have filed a patent infringement suit for Intellectual Ventures against Google Inc.’s most expensive acquisition: Motorola Mobility Inc.

The nonpracticing entity started by former Microsoft executive Nathan Myhrvold filed suit in Delaware federal court on Thursday. IV said in its complaint that it tried to negotiate a licensing deal with Motorola beginning in January, but couldn’t reach an agreement.