Microsoft's Bing is to power Yahoo's sites, a joint engineering team will begin adapting Bing for the Yahoo site, and hopefully the engine is added to the Yahoo site by the end of this year

Google spokesman Adam Kovacevich said the search company welcomes the new competition. "There has always been robust competition in our industry, which keeps us on our toes and benefits users," wrote Kovacevich. "We compete against a number of alternatives, including traditional search engines, vertical search sites, social networks, and other forms of online and offline advertising."