Bing will start powering Internet searches at Yahoo! web pages in North America this week as the technology firms combine forces to take on Google.
"Later this week, we will begin transitioning the back-end technology for Yahoo! Search in the US and Canada (English) over to the Microsoft platform," Yahoo! search product operations vice president Shashi Seth said in a blog post.
"Keep an eye out for the 'Powered by Bing' indicator at the bottom of our search results page, which will indicate that you are viewing listings from Microsoft."
Yahoo! will control how results are presented and has vowed to give users relevant data customized to their tastes or interests.
Yahoo! and Microsoft unveiled a 10-year Web search and advertising partnership a year ago that set the stage for a joint offensive against Google.
Under the agreement, Yahoo! will use Microsoft's search engine on its own sites while providing the exclusive global sales force for premium advertisers.
Data released on Tuesday by industry tracker comScore showed that US search engine rankings changed slightly in July, with Google's dominant share slipping less than half a percent to 65.8 from 66.2 percent in June.
The comScore rankings were based on "explicit" searches in which people entered specific queries to scour the Internet for information.
Google's loss was apparently a gain for Yahoo!, which had a 17.1 percent share of the search market as compared to 16.7 percent the previous month, according to comScore.
Microsoft remained in third place with its search market share unchanged at 11 percent, according to comScore figures.
US Internet users conducted a total of 15.6 billion "explicit" searches in July, with Google handling 10.3 billion while Yahoo! tended to 2.7 billion and Microsoft fielded 1.7 billion.
Explore further: Microsoft's Bing increases US search share