Deloitte are already an official sponsor of the 2010 Vancouver Winter Olympics and 2012 London Games.

The latest deal will also cover sponsorship of the 2010 Olympic and Paralympic teams, as well as the 2011 US Pan American team and the 2010 team for the Youth Olympic Games in Singapore.

As the official professional services Sponsor of audit, tax, consulting and financial advisory services, Deloitte's subsidiaries will contribute by offering a variety of in-kind professional services to the USOC.

Barry Salzburg, the chief executive of Deloitte, said: "We believe the business community has a powerful role to play in answering the call to service to help nonprofit organisations deliver results.

"There is no better opportunity to put the intellectual capital and business knowledge of our people to work than through the delivery of our exceptional professional services capabilities for the strategic, operational, and financial benefit of the USOC and US Olympic and Paralympic athletes and hopefuls."

Stephanie Streeter, the acting chief executive of the USOC, said: "We are proud to welcome Deloitte to our family of sponsors and appreciate the expertise and support they bring in preparing America's athletes for the Vancouver 2010 and London 2012 Olympic and Paralympic Games.

"This contribution and the breadth of capabilities they bring will be instrumental in our mission to enable America's athletes to realize their Olympic and Paralympic dreams."