Kayak Will Power Flight Search On Bing

Microsoft’s Bing is turning to Kayak to power one of the most high-profile features on its site. Under an agreement announced today, Kayak “will provide flight search results in the U.S. from multiple cities, airports and airlines” on Bing Travel, a vertical that Microsoft (NSDQ: MSFT) has heavily promoted since relaunching its search engine as Bing in June 2009.

Microsoft says the deal will let it “focus our development resources on delivering even more unique and valuable features for customers” and that it will be keeping features like price predictor, which tells users whether the price of a flight is likely to rise. It acquired that technology (as well as much of the foundation for what currently makes up Bing Travel) when it purchased Farecast three years ago.

It’s worth emphasizing, though, that Microsoft is essentially outsourcing flight search to a company that once was a fierce competitor — and which at one point had even accused Microsoft of copying some of its features. Over at TNooz, Dennis Schaal speculates that the deal may have been prompted by a desire by the two companies to counter Google’s pending purchase of travel search technology provider ITA Software.

The deal, however, is also part of a strategy by Microsoft to partner with third-parties to add features to its search engine. Just yesterday, Microsoft said it had partnered with discount aggregator TheDealmap to show local deals to users when they search for a business that has a discount available.