Yahoo will become T-mobile's default mobile search provider across its European markets by the end of next month.

Yahoo's oneSearch product will be provided to T-Mobile customers in place of current offerings. In addition, the company will offer mobile versions of its services including Flickr, Messenger, Mail, weather and finance.

Financial terms of the deal have not been disclosed.

The announcement is a big win for Yahoo over Google, which previously was the search provider of choice for T-Mobile. With the addition of T-Mobile, one of the largest carriers in the world, Yahoo's mobile products would reach nearly 600 million potential customers.

Yahoo says it hopes to grow that number to 750 million by the end of this year, and 1 billion by 2009. If it is successful in doing so, it will likely become the de-facto leader in mobile Web search, considering the total number of mobile suscribers are right around 2 billion worldwide.

Over the next year, Yahoo plans to market its mobile offerings heavily in order to promote use among those who have access to its services, but do not necessarily utilize them.

Google will be walking away from the Mobile World Congress in Barcelona far from empty-handed, however: it signed a deal with major manufacturer Nokia to integrate its search into that company's phones.