BlackBerry maker Research In Motion Ltd sued Motorola Inc over claims the mobile-phone maker is improperly blocking it from offering jobs to laid-off Motorola workers, Bloomberg said.

RIM, in a complaint filed in state court in Chicago, asked for an order invalidating an agreement the companies reached this year not to solicit each other’s employees, the agency said.

The agreement expired in August and is no longer enforceable, the agency said, citing the complaint.

Motorola is improperly trying to expand the agreement “to prevent the RIM entities from hiring any Motorola employees, including the thousands of employees Motorola has already fired or will fire,” RIM was quoted as saying in the complaint.

Ah, the holiday spirit in Silicon Valley.