On September 16, 2013, WilmerHale attorneys obtained a significant victory for OpenMarket Inc., a subsidiary of the firm's client Amdocs Inc., when Judge Allison Nathan of the United States District Court for the Southern District of New York granted OpenMarket's motion to stay pending arbitration. OpenMarket, along with 16 other parties, was sued by a group of putative class action plaintiffs for alleged violations of the Sherman Antitrust Act. Judge Nathan's decision requires any claims against the defendants to be pursued in individual arbitrations on a non-class basis, and not in federal court. Judge Nathan rejected all of plaintiffs' arguments and granted OpenMarket all of the relief sought. In a 52-page opinion, the judge concluded that "all plaintiffs must arbitrate their disputes with OpenMarket." Named plaintiffs indicated to the court that if forced to arbitration they would not pursue their claims. She also granted the motions of other defendants, who had relied on other arbitration clauses to make similar arguments.

The WilmerHale team included Partners Molly Boast, Sanket Bulsara, and former Associate Christina Milnor.