LONDON – Yahoo has struck a deal with wireless provider T-Mobile to put ads on subscribers’ handsets starting this summer.

Beginning in July, T-Mobile users will see targeted, graphical ads when they use web’n’walk, the operator’s mobile Internet service, the companies said. Advertising will be sold by Yahoo, but the companies did not detail the potential value of the agreement.

Last March Yahoo launched Mobile Publisher Services, a set of services for publishers, advertisers and network operators for distributing and making money from mobile advertisements. Yahoo made a deal with Vodafone in November 2006 to be its exclusive provider of mobile ads in the U.K.

Other companies, including Google, Microsoft and AOL, see growth in the mobile advertising market, and all have made investments in technology needed to distribute ads.

The companies see potential in supplying several types of ads — such as banner, sponsored search and video — to those accessing the Internet through mobile devices.

One focus is behavioral targeting, or delivering ads expected to interest people based on metrics such as what Web sites they visit, where they live and the topics they read about. The potential of such targeting has raised privacy concerns for some.

The mobile advertising market in Europe, excluding SMS (Short Message Service) and MMS (Multimedia Messaging Service) ads, will be around