At today's launch to present the competition format and regulations, organizers said preliminary sailing will start in June with the challengers series trials starting in May 2009.

There will be a new class of America's Cup yachts, the first since 1992, with the top six teams advancing to the semifinals. A three-round format will determine who is in the Challengers finals.

The winning boat will then sail against Alinghi, the two-time defending champion from Switzerland, for the Auld Mug in a best-of-nine, match-race format from July 18, 2009.

"We are pleased to announce an event format that will produce more sailing than ever before and hopefully will stimulate new teams to enter the competition," America's Cup Management chief executive Michel Hodara said.

Desafio Espanol, Team Origin of Britain, Team New Zealand, United Internet Team Germany and Shosholoza of South Africa have already entered and took part in the six-week process to draw up the regulations.

A new twist will include Alinghi racing the defeated challengers in a parallel act to the ongoing trials series. Previously, the defending champion only raced in the America's Cup final after the acts had concluded.

ACM also limited the number of sails each team may produce and outlawed two-boat testing. Teams will instead have to use "practice testing" between syndicates to try out their new boats. The practice sessions will run from next October through April 2009.

The schedule could still change depending on the outcome of the lawsuit brought by the Golden Gate Yacht Club — home of BMW Oracle Racing — against Alinghi's club, the Societe Nautique de Geneve.

The San Francisco-based syndicate claims that Spanish boat Desafio Espanol — which helped establish the 33rd edition's format — is an "invalid challenger."

If Golden Gate wins the lawsuit, it would then be able to re-negotiate the format with Alinghi.