Icahn is trying to obtain documents related to Motorola's corporate strategy on mobile phones and hiring practices for top executives, the Chicago Tribune reported Tuesday.
Icahn, who lost a proxy battle for a seat on the Motorola board a year ago, has increased his share of the company to 6 percent and is attempting to win four seats on the board this year.
Icahn contends Motorola should split from its hand-held devices business.
Icahn recently wrote shareholders company management made "empty promises," in "a year of revolving-door executives, a leadership vacuum and accelerating deterioration at Motorola's Mobile Devices unit."
"You'd spin it off and it would certainly keep the brand," Icahn told the Tribune Monday. "It's a great brand with great intellectual property. It just needs someone to run it properly."
Motorola refused Icahn's earlier request for documents because it did not "set out a proper purpose to support a right of inspection under Delaware Law."
Icahn said he would file his suit in the Delaware Chancery Court, the report said.