Attorneys for shareholders of UnitedHealth Group Inc. (UNH) asked a federal judge for $110 million in fees for their work on a $925.5 million settlement of a lawsuit alleging improper backdating of stock options.

The investors sued UnitedHealth and certain officers and directors in 2006, claiming that the Minnetonka-based insurer failed to disclose stock-option backdating in violation of securities laws.

UnitedHealth agreed in July to pay $895 million to settle the suit, which was followed two months later by a $30 million settlement by former Chief Executive Officer William McGuire.

"By any measure, the settlement is record-breaking and provides a substantial benefit to the class," lawyers for the investors said in a Jan. 28 court filing.

U.S. District Judge James Rosenbaum in Minneapolis granted preliminary approval of the settlement in December. A hearing for final approval is set for March 16. The fee request represents about 12 percent of the recovery and is based on a 2007 agreement with the lead investor plaintiff, the California Public Employees' Retirement System, lawyers from the law firm Coughlin Stoia Geller Rudman & Robbins said.