SAN JOSE, Calif. - It was 2001, and the nation's No. 2 phone company badly needed to boost its Internet cachet. So SBC Communications made a sweetheart deal with Yahoo. In exchange for a co-branded portal featuring Yahoo e-mail and other services, SBC agreed to pay Yahoo a monthly fee "in perpetuity" for each customer who signed up for online access.

Six years later, SBC is no longer desperate. Now called AT&T, it is the biggest phone company in the United States as well as the biggest wireless carrier.