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.