A New York judge yesterday ruled that the next America's Cup cannot be held in Ras al-Khaimah, one of the United Arab Emirates, because yachting rules dictate it must be held in the southern hemisphere.

Two rival teams scheduled to face off in February in yachting's most prestigious race have been tangled in a long legal battle over the terms of the race. Yesterday's ruling adds a new layer of uncertainty.

"Since RAK is in the northern hemisphere, it cannot under the Deed of Gift take place in RAK," said New York State Supreme Court Justice Shirley Kornreich, using an abbreviation for the emirate.

The judge declined to discuss challenger BMW Oracle's contention that holding the race in Ras al-Khaimah would have created a security risk for US sailors due to possible attacks from al Qaeda or other militant groups.

Defending champion Alinghi, which sails under the colours of Societe Nautique de Geneve and is backed by biotechnology billionaire Ernesto Bertarelli, declined to say whether it planned to appeal.

A spokesman for California team BMW Oracle, which sails under the colours of the Golden Gate Yacht Club and is backed by Oracle CEO Larry Ellison, said they expected the race to be moved to Valencia, Spain.

Previous court rulings have named Valencia as an alternative venue. Though Spain is in the northern hemisphere, Valencia has been deemed acceptable because it was the site of the previous race in 2007.

The two sides also argued over how boat measurement guidelines should be applied, and Kornreich said she expected to issue a ruling on that issue by the end of the week.