Williams title sponsor moves to Red Bull
Williams driver Bruno Senna of Brazil, steers his car during the Monaco F1 Grand Prix, at the Monaco racetrack, in Monaco, Sunday, May 27, 2012.
The American multinational telecom became Williams' naming backer in 2007, but left the Oxfordshire based team after its dire 2011 campaign.
Red Bull announced in Monaco that the company has now joined the Austrian energy drink-owned team as an official technical supplier.
"Red Bull Racing is excited to work with an innovative, global and reputable brand such as AT&T," said team boss Christian Horner.