Michael Phelps said Wednesday that he has decided to reduce to five the number of individual events he plans to swim at the Olympics next month, easing his workload but still facing challenges to his quest for seven gold medals.

Phelps, 19, of Baltimore County, said he is eliminating the 200-meter backstroke from his Athens program. That removes three races from his task, including heats and semifinals, but leaves tough matchups against record-holding rivals.

The decision came at the end of the Olympic trials here, in which Phelps set one world record, swam superbly in most of his 17 races, but lost two important contests, and at the very end appeared hampered by the eight-day grind.

The decision also sets up probable Olympic battles between Phelps and Australian superstar Ian Thorpe in the 200 freestyle, and Phelps and American world record holder Ian Crocker, who beat Phelps Tuesday night in the 100 butterfly and set a world record in the process.

Phelps has been offered $1 million by Speedo if he wins seven gold medals next month, matching the feat of Mark Spitz. Losses to either Thorpe or Crocker could reduce those chances.

But after decisive losses to Crocker, and to Californian Aaron Peirsol in the 200 backstroke Monday night, when Phelps swam three races in about 90 minutes, he and coach Bob Bowman sat down and rethought their program.

"Michael did actually physiologically seem to be better through the week," Bowman said after the decision was announced. "But after the night where he swam three events in one session, the following day he really felt it."

Bowman, who was named an assistant coach for the Olympic team Wednesday night, said he knew what he was going to decide before he left the pool Tuesday night following Phelps's loss to Crocker. "Michael and I met at breakfast . . . and discussed it again," he said. "We were totally on the same page."

The trials program, which ended Wednesday, was almost a carbon copy of the swimming program in Athens. Dropping the 200 backstroke saves Phelps from swimming in three races on the night of Aug. 19 in Athens, Bowman said.

The 200 backstroke is sandwiched that night between the 100 butterfly semifinal and the 200 individual medley final, probably Phelps's best event and one in which he holds the world record.

"To enter five [individual] events at the Olympic Games is historic in itself," Bowman said. "To qualify for six is very amazing, but to try to swim five, plus relays, will be plenty."

"I feel that Michael's signature event is the 200 IM and I think he deserves to be able to swim that without having done an all-out 200 back[stroke] right before it. He deserves to give the world a fantastic 200 IM."

Bowman said he could never forgive himself if Phelps raced the 200 backstroke, lost by a narrow margin and then was beaten in the 200 IM because he was tired. "That would be reckless on my part," he said.

The odds, though, are against Phelps in the 200 freestyle, and, perhaps, the 100 butterfly, too.

Thorpe's world record of 1 minute 44.06 seconds is almost two seconds faster than Phelps's American record of 1:45.99. Holland's Pieter van den Hoogenband, another potential contestant, also has finished the event faster than Phelps. Grant Hackett, another Australian, could also be a strong competitor.

Phelps on Wednesday said he was game anyhow.

"One thing I always wanted to do was race Thorpe in a freestyle event," Phelps said. "It's something that I haven't had the opportunity to do so far in my career. I think this is probably the best opportunity for me to be able to swim in probably the fastest 200 freestyle heat in history."

In addition to the 200 freestyle, the 100 butterfly and the 200 individual medley, Phelps plans to swim the 400 individual medley and the 200 butterfly, in which he also holds the world record.

Phelps also said he wants to be on all three Olympic relay teams: the 400 freestyle, the 800 freestyle and the 400 medley. U.S. teams have done well in the 400 relays, but the Australians have ruled the 800 relay. The decision on who will race on the relay teams will be made later at the Olympics.

If Phelps and the Americans should lose that relay, and Phelps loses either the 200 freestyle or the 100 butterfly, he could wind up with only six gold medals.

Bowman said the new program doesn't threaten the hunt for seven gold medals any more than any other potential Phelps program. "It's always going to include taking on some giants in their event," he said. "The question is how many can you take on?"

Phelps's decision and his performance here have not dimmed corporate enthusiasm. Phelps, who already has made millions in endorsements, was introduced here Wednesday by supermodel Cindy Crawford as a "brand ambassador" for Omega, the Swiss watch company.

Phelps, who has numerous other sponsors, was presented a $3,495 Omega Seamaster watch by Crawford, who slipped the watch over the swimmer's tanned left wrist. "Pretty swell watch," the swimmer said, "I'll tell you that."

As Phelps grinned with Crawford, his mother, Debbie Phelps, sat in the audience.

"This chapter is finished," she said. "This is done. This is closure. Now we're opening the next."

After 17 races in eight-day U.S. trials, Michael Phelps -- who stands to make $1 million from Speedo -- will trim at least three races from his Athens plans.