Accommodation listed on Hotels4u.com will be streamed through the main Thomas Cook website within weeks.
Thomas Cook Group acquired the independently owned bedbank this week in a £21.8 million deal.
Stock from Hotels4.com and the trade-only ThomasCookHotels.com will be shared once integration is complete, a spokeswoman confirmed.
However it is understood the Hotels4u.com brand will be pushed via ThomasCook.com in order to grow its consumer presence.
There are no plans as yet to open ThomasCookHotels to consumers. The existing FlexibleTrips dynamic packaging brand is also likely to take Hotels4u.com inventory.
Hotels4u.com currently has around 30,000 properties on its book and handles around 500,000 customers each year.
Thomas Cook Group chief executive Manny Fontenla-Novoa said: “This is an acquisition that fits perfectly with our strategy of enhancing Thomas Cook’s position in the independent travel sector and will also further strengthen our mainstream business.”
The deal was completed on Wednesday this week and announced to the London Stock Exchange on Thursday.