Google, Yahoo, and Microsoft announced separate deals this week with telecoms operators to place their search engines on handsets.

Google announced a deal to put its search function on 3mobile's handsets, and extended testing its mobile internet advertising to cell-phone subsribers in eight additional countries, including China and several European nations. The ads will appear whenever someone in those countries use a cell phone's internet capability to access a site or to search via Google's engine, the company announced Wednesday, reports MarketWatch.

According to the Financial Times, Sprint Nextel, the US carrier, said it would place Microsoft's search engine on its mobile phones, while Yahoo began testing graphical cell-phone ads with U.K. service provider Vodafone, claiming to have once again upped Google.

Google, Yahoo, Microsoft are racing to form alliances with mobile operators to provide ad-supported services in an industry that's expected to be worth $11 billion by 2011, according to a recent Informa Group report.