-By Mike Shields, Mediaweek

NEW YORK Microsoft said it would provide search functionality and search advertising on Facebook as part of an extension of the ad partnership forged by the two companies in 2006.

The deal, announced at Facebook's f8 Developer Conference in San Francisco, represents an opportunity for Microsoft to boost its anemic share in the space -- though it may not provide a financial windfall. Terms of the deal were not disclosed.

Microsoft accounted for 9.2 percent of searches in June, per comScore, versus a 61.5 percent share for Google. Placing a Live Search box on thousands of Facebook pages -- which should happen by the end of this year, said officials -- would likely bolster that share number, given that the social-networking site reaches 37 million-plus monthly unique users.

However, two years ago Google signed an exclusive $900 million search ad deal with MySpace, which the company has since complained about as being difficult to cash in. It appears that social-network users are not necessarily inclined to search for products and services while visiting such friend-centric environments (Facebook has never included Web search).

Besides search, Microsoft is the exclusive third-party seller of remnant ad inventory on Facebook. Last year, the companies deepened their relationship when Microsoft agreed to invest $240 million in the company.