A group of pension funds reached a settlement Monday with Mercury Interactive Corp. for $117.5 million related to the backdating of stock options, the group’s law firm said.

The settlement is the largest in the history of backdating class action lawsuits, said Christopher Keller, a partner at Labaton Sucharow LLP, which represented the funds. It was more than six times larger than the largest previous backdating settlement, which totaled $18 million.