The hotel industry in the United States is going after travel websites like Expedia and Priceline, according to documents seen by Bloomberg.
Shares of Expedia and Priceline closed slightly negative on Friday. Trivago's stock closed down more than 1 percent.
The American Hotel & Lodging Association, which counts Marriott and Hyatt as members, believes that the booking companies are monopolistic, and is looking to lobby against them.
"We have publicly opposed such consolidation with the Justice Department and outlined how the Expedia and Priceline duopoly hurts consumer choice and the small businesses in our industry, which represent some 60 percent of all the hotels in the U.S., who are struggling to compete as a result of the gouging commission rates charged by the [online travel agencies]," the American Hotel & Lodging Association said.
According to Bloomberg, the documents said potential marketing for the hotel group's effort could have a Monopoly game theme featuring Expedia and Priceline "to better underscore that the individual companies are really owned only by two major players."
The American Hotel & Lodging Association also pushed for lawmakers to pass the Stop Online Booking Scams Act, which was introduced last year and would require third-party travel sites to disclose to customers that they aren't actually the hotels' websites. The group says such websites can be deceptive, resulting in "lost reservations, extra charges or alternative accommodations."
"Listing on our platforms is completely optional and free," a spokeswoman for the Priceline Group, Leslie Cafferty, told CNBC.
Sarah Gavin, vice president of communications at Expedia, told CNBC that the company plays "a small part" in the travel market.
As of Friday's close, shares of Expedia are up nearly 24 percent year-to-date, while Priceline shares rose nearly 30 percent in the same period.
Read Bloomberg's full report here.
Expedia shares 5-day performance
Priceline shares 5-day performance
CNBC's Susan Li contributed to this report.