Microsoft Corporation, the world's biggest software manufacturer, has acquired Greenfield Online Inc., the owner of European price comparison site Ciao GmbH, for total consideration of about $486 million, to boost its Internet search and e-commerce business in Europe.

Microsoft, whose $47.5-billion bid to buy Yahoo this year failed after a lengthy battle, is hoping that latest acquisition would benefit its Live Search platform.

Presently, Internet search market is commanded by Google, which has 62% of the global search market and 79% in Europe, according to the most recent data published by Web usage tracker ComScore.

Ciao.com is a multi-million-strong online community that critically reviews and rates millions of products and services for the benefit of other consumers. The company is active in seven European countries and attracts 19.6 million unique visitors per month in Europe.

To lure more customers, Microsoft also plans to reward users, who buy products through its shopping sites by offering cash back. The companies expect to close deal during the fourth quarter of 2008.