Several hotel-casino operators on the Strip asked a U.S. court last week to dismiss a lawsuit accusing the companies of price fixing hotel rooms through a revenue management platform.

Lawyers representing MGM Resorts International, Caesars Entertainment Inc., Wynn Resorts Holdings, Treasure Island and Cendyn Group, the company behind the revenue management platform Rainmaker, said in a court filing on March 27 that the plaintiffs, two tourists, did not show any direct evidence that using the platform led to price collusion.

The attorneys did not immediately respond to a request for comment.

“The complaint fails at the outset because it is missing every essential ingredient necessary to plead an antitrust conspiracy,” under precedent, defendants said in a joint motion to dismiss the U.S. District Court of Nevada case.