Expedia Inc, owner of the largest U.S. online travel agency, and InterContinental Hotels Group Plc, the world's largest hotelier, have entered a deal that offers its rooms on Expedia sites globally, the two companies said on Thursday.

The agreement adds more than 3,700 hotels across all IHG brands, including InterContinental Hotels & Resorts, Crowne Plaza, Hotel Indigo, Holiday Inn, Holiday Inn Express, Staybridge Suites and Candlewood Suites to the inventory on Expedia.

The InterContinental properties have been available on Expedia's Hotwire.com site but have not available on Expedia in more than three years.

The rooms will be available on Expedia Corporate Travel by December, with all participating hotels becoming available on Expedia and Hotels.com branded sites in 2008.