Choice Hotels International Inc., Hilton Worldwide Holdings Inc., Hyatt Hotels Corp., InterContinental Hotels Group PLC, Marriott International Inc. and Wyndham Worldwide Corp. are facing a class-action lawsuit alleging that the companies colluded to curb competition and hike prices by manipulating internet search results.

Law firm Hagens Berman Sobol Shapiro LLP said in a release that the suit was filed in the U.S. District Court for the Northern District of Illinois March 19 and involves roughly 60% of all hotel room inventory in the U.S.

According to the lawsuit, the hotel companies entered into an anti-competitive agreement to eliminate online branded keyword-search advertising against each other, thereby reducing the free flow of competitive information, increasing prices for hotel rooms and raising the cost of finding hotel rooms.

Apart from seeking reimbursement for consumers, the lawsuit seeks an injunction from the court to "force the hotel chains to end their deceptive marketing practices," the firm said.