SAN FRANCISCO (AP) — Louis Vuitton is paying the America's Cup $3 million less than originally agreed to sponsor the challenger trials for sailing's marquee regatta because only three teams are entered.

America's Cup CEO Stephen Barclay said Friday that the contract was amended in April when it became clear how few teams would make it to the starting line. Louis Vuitton would have paid the full amount originally contracted if at least five challengers entered.

Barclay declined to disclose what the French luxury goods maker is paying to sponsor the series, which will determine the opponent for defending champion Oracle Team USA in the 34th America's Cup starting Sept. 7.

But he said sponsorships of this type are generally worth tens of millions of dollars.

He added that the reduced sponsorship fee won't affect the sailing.

Louis Vuitton has sponsored the challenger series since 1983.

The regatta has gotten off to a troubled start. Artemis Racing's Andrew "Bart" Simpson was killed in a capsize on May 9 that destroyed the Swedish-based syndicate's first boat. Artemis is still about a week away from beginning sea trials on its second boat and might not be ready to sail until the Louis Vuitton Cup semifinals in early August.

Although the Louis Vuitton Cup started Sunday, Saturday will be the first time two boats have been together on the race course together when Emirates Team New Zealand is scheduled to face Italy's Luna Rossa.

The Italians boycotted the opening race against the Kiwis on Sunday while they awaited an international jury's decision on a rules spat. Team New Zealand sailed around the course alone that day to collect the first point of the regatta.

The Kiwis also sailed around alone on Tuesday when Artemis was their scheduled opponent, and the Italians did the same on Thursday.