Berlin  - The United States was disqualified from the men's 4x100 metres relay race at the world championships over a faulty baton exchange on Friday night.

The British team protested that the final exchange between Sean Crawford and Darvis Patton was completed outside the exchange zone, which was granted by race officials.

The United States has lodged an appeal against the disqualification.

The US team originally won the heat in 37.97 seconds to make Saturday's final. Britain came second in the race and went through as well.

A disqualification would be latest disaster for the men's relay which dropped the baton at the 2008 Olympics as Usain Bolt's Jamaica cruised to gold, a feat they can repeat on Saturday.  (dpa)