IRVINE: US swim star Michael Phelps, who won eight gold medals at the 2008 Beijing Olympics and six more at the 2004 Athens Games, takes his next strokes toward the 2012 London Olympics starting Tuesday.

Phelps is among more than 30 Olympians set to compete at the US National Swim Championships, a five-day meet that serves as the selection for the Pan Pacific Championships at Irvine on August 18-22.

The Pan Pacific showdown against top rivals from Australia, Japan and more than 20 other countries will be used with the US nationals results to decide an American squad for the 2011 World Swim Championships in Shanghai, the last major global showdown before the London Olympics.

Phelps has not yet decided exactly what events he might contest in England, except to say he will not try to win eight races again, but the first clues to his London lineup might be seen in the next three weeks.

"Practice has been going very well," Phelps said.

Among the other US stars looking to secure national titles and spots at the Pan Pacific and 2011 worlds include Olympians Ryan Lochte, Aaron Peirsol, Natalie Coughlin, Rebecca Soni, Jason Lezak, Amanda Beard, Katie Hoff and Cullen Jones.

BDST: 1105 HRS, AUGUST 02, 2010