Microsoft has agreed to buy Greenfield Online, owner of European price comparison website ciao.com, for about $486 million to boost its Internet search and e-commerce business in Europe.

Microsoft said on Friday the acquisition should benefit its Live Search platform.

"The team at Ciao has built a passionate consumer community based on intuitive technology and extensive merchant relationships that we believe will deliver incremental benefit to the Microsoft Live Search platform," said Microsoft's vice president for Windows and online services, Tami Reller.

Ciao.com offers advice on purchases, mainly of consumer electronics, and encourages users to join a network of shopping experts to share opinions. It makes its revenues from e-commerce, merchant referrals and advertising sales.

The companies expect both deals to close during the fourth quarter of 2008.