Priceline investing $500 mln in China's Ctrip

US online booking service Priceline Group has agreed to pay US$500 million as part of a deal that would give it a stake of up to 10 percent in China's travel service provider Ctrip.com.

The move comes as Priceline and Shanghai-based Ctrip broaden their working partnership, allowing Ctrip's customers to reach Priceline's portfolio of offerings.

Under the terms of the deal, the two companies will offer their respective hotel inventory to each other on a broader scale, including an agreement to boost promotion.

In addition, Ctrip will provide access to Priceline's rentalcars.com and OpenTable inventory, and Priceline will promote Ctrip's air ticketing services to its customers. Priceline will have the right to nominate an observer to Ctrip's board.