The travel off-shoot of Microsoft's new search engine Bing, is coming under fire for being a little too similar to established airfare and travel site Kayak.

The similarities of certain areas of Bing to Kayak's look, feel and functionality is so much so that it could lead to a legal battle as Kayak execs move to defend the site from the perceived plagiarism.

Kayak's chief marketing officer, Robert Birge, told that they had been in touch with the Bing team regarding the issue.

"We have contacted them through official channels about concerns about the similarities between Bing and Kayak. From the look and feel of their travel product, they seem to agree with our approach to the market", Birge said.

Microsoft has confirmed that dialogue has opened up between the two companies, with Microsoft spokesperson Whitney Burk stating: "We are discussing the matter with Kayak".

"Bing Travel is based on independent development by Microsoft and, which Microsoft acquired in 2008. Any contrary allegations are without merit".