Microsoft's Roger Wong (2nd R) demonstrates maps using Bing at the 2010 International Consumer Electronics Show at the Las Vegas Convention Center January 2010 in Nevada. Microsoft said Friday that Bing will power Internet searches for Facebook's 400 million members in an arrangement that returns control of display advertising to the social-networking service.

Microsoft said Friday that Bing will power Internet searches for Facebook's 400 million members in an arrangement that returns control of display advertising to the social-networking service.

Bing had previously powered online searches on US Facebook pages.

will provide Facebook users full access to Bing features as part of an "expanded cooperation in search," according to Bing general manager Jon Tinter.

"You will start to see the fruits of our expanded relationship show up in the Facebook experience over the weeks and months ahead," Tinter said in a blog post.

The companies mutually agreed that Facebook will take over selling display advertising posted at the website because it "just made more sense" given the unique nature of the website, according to Tinter.

Microsoft's control of display served up at Facebook stretched back to shortly before the US software giant bought a 1.6-percent stake in in 2007 for 240 million dollars.

That arrangement was inked in a contract that was up for renewal. Microsoft launched its new Bing last year.