Microsoft could invest heavily to improve its web search engine to rival Google, even if it fails in its bid to acquire Yahoo. According to chairman Bill Gates, Google is the only serious contender in the search market and Microsoft needs a bigger presence to create a more competitive and profitable web-search business.

"We can afford to make big investments in the engineering and marketing that needs to get done. We will do that with or without Yahoo," Gates told Reuters.

"But we also see that we'd get there faster if the great engineering work that Yahoo has done and the great engineers there were part of the common effort," added Gates.

Microsoft made an unsolicited $44bn bid to acquire Yahoo and claimed it was a "full and fair" offer. However, Yahoo's board rejected the offer saying it substantially undervalued the company.