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

Microsoft, whose $47.5 billion bid to buy Yahoo earlier this year failed after a long battle, said the acquisition - the latest in a series - should help it build a more consumer-friendly, results-oriented search engine.

'We call it 'instant answers',' said Microsoft consumer and online business in Europe head John Mangelaars.

Internet search is dominated by Google, which has 62 per cent of the global search market and 79pc in Europe, according to web usage tracker ComScore.

Microsoft has a 2pc market share in Europe and 9pc worldwide, behind both Google and Yahoo.

In Europe, Microsoft is also outranked by online auction site eBay and Russia's Yandex.

But Mangelaars said buying ciao.com was an important step in Microsoft's attempt to distinguish itself by providing search results more useful to consumers, particularly shoppers, than those thrown up by a Google search.

For example, results of a Microsoft search for a particular camera model could include which prices were available from which retailers, and maps of where those retailers were, rather than just links to the manufacturer's and retailers' websites.

The acquisition follows those of Norwegian enterprise search company Fast for about $1.2bn early this year and shopping-and-auction site jellyfish.com for an undisclosed sum last year.

Caio.com is active in seven European countries and attracts 19.6m unique visitors per month in Europe, more than twice as many as rival kelkoo.com.

To attract more users, Microsoft also plans to reward consumers who buy products through its shopping sites by giving them cash back, extending a trial started in the US a few months ago.