Single-serve coffee brewers and the “pods” that fuel them are big business, especially now that market leader Green Mountain Coffee Roasters Inc.’s patents on the technology have expired. So it’s fitting that one of Green Mountain’s upstart competitors has hired a big-name litigator, Dan Webb of Winston & Strawn, to challenge Green Mountain’s recent efforts to maintain its huge market share.

In a lengthy complaint filed Tuesday in U.S. district court in Manhattan, Winston & Strawn client Treehouse Foods Inc. alleges that Green Mountain is violating antitrust laws by forcing business partners at every level of its distribution chain into anticompetitive agreements. Treehouse also alleges that Green Mountain is trying to stifle competition by making its Keurig coffee brewers incompatible with pods sold by rivals.