T-Mobile USA will provide Yahoo’s OneSearch search engine on its phones, a Yahoo executive said Wednesday.

T-Mobile is placing a OneSearch button on its phones in a deal that is to be announced soon, said Marco Boerries, executive vice president and head of Yahoo’s Connected Life Division, at the Open Mobile Summit conference in San Francisco. The carrier’s decision to place a OneSearch button in the software of its subscribers’ handsets is a much-needed win for Yahoo as it struggles against Google and Microsoft for search advertising dollars and looks for a successor to outgoing CEO Jerry Yang.

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