MADRID (AFP) - US team Oracle's giant trimaran broke its mast in an accident during training off San Diego, California, the America's Cup challenger said Wednesday.

The accident on Tuesday comes just three months before Oracle is due to face Swiss defender Alinghi in a three-leg duel to decide the 33rd edition of yachting's most prestigious trophy.

Oracle said there were no casualties and that the broken 185-foot (55-metre) mast had been recovered.

"Right now, it's too early to say why and where it failed," said helmsman James Spithill.

"The biggest priority was making sure everyone was safe and getting back to the dock and now we'll evaluate (what happened)."

Oracle crew began training on the 90-foot (27-metre) yacht off San Diego back in September, 2008.

Alinghi and Oracle have been locked in a two-year legal battle over the next edition of the Cup.

The New York Supreme Court ruled in April that the Cup should be settled by a one-on-one multihull duel next February instead of the traditional fully-fledged regatta with several teams.

However, the two sides remain in dispute over the venue.

The New York court has ruled that the event cannot take place in the Gulf emirate of Ras al-Khaimah as planned by Alinghi.

The Swiss syndicate, which has brought its giant catamaran to Ras al-Khaimah, said Tuesday it plans to appeal that decision.

In a newspaper interview published Wednesday, Alinghi's owner Ernesto Bertarelli again accused Oracle of trying to buy time with repeated legal action over their duel.

"They want to win the Cup and obviously believe that their best chance of reaching it is before the courts and not on the water," he told the Swiss daily Le Matin.

"I think that when they discovered our new boat, they realised they were lagging behind. The latest legal proceeedings allow them to play for time in a bid to catch up," the Swiss billionaire added.

Bertarelli admitted that he often had moments when he felt like giving up in the midst of the legal battle.