* Vietnam launches first dispute at WTO
* U.S. anti-dumping method once again targeted
* Vietnam defends key export (Adds detail on size of U.S. duties)
By Jonathan Lynn
GENEVA, Feb 2 (Reuters) - Vietnam has launched its first dispute at the World Trade Organization with a case against U.S. anti-dumping measures on its key exports of shrimp.
The communist state only joined the global trade arbiter three years ago, and its economy like China's has benefited strongly from membership in the world trading system and its rules.
The trade dispute with the United States not only has symbolic significance, given the two countries' war that ended 35 years ago, but defends a product that brought in some $1.5 billion in exports last year.
It also pits Hanoi against a large number of Vietnamese-American shrimpers who operate off the coasts of Texas, Louisiana, Mississippi, Alabama, Georgia and Florida.
No one was available for comment at Vietnam's mission to the WTO, and details of the dispute were not immediately clear.
Vietnamese shrimp exporters currently face U.S. anti-dumping duties ranging from zero to about 26 percent.
They have complained in the past about the controversial U.S. method of calculating anti-dumping duties known as zeroing, which has been condemned repeatedly by WTO courts and rejected by all other WTO members.
"The WTO has concluded that the U.S. was wrong in applying the zeroing method in precedent cases. I can see high possibility of Vietnam winning the case," Nguyen Huu Dung, deputy chairman of the Vietnam Association of Seafood Exporters and Producers (VASEP), told the VietNamNet website last year.
Vietnam will also gain useful experience in international trade litigation from fighting a WTO case, Dung said.
According to documents filed by Vietnam with the WTO, Vietnam is seeking consultations with the United States -- the first formal stage in a dispute.
A spokeswoman for the U.S. Trade Representative's office said they were reviewing Vietnam's request for talks, but provided no further information.
If the two sides fail to resolve the dispute through bilateral consultations in 60 days, Vietnam can ask the WTO to set up a panel to rule on the case.
PLUMMETING PRICES
VASEP estimates Vietnam exported 190,000 tonnes of shrimp in 2009, up 7 percent in volume and 1 percent in value. Besides the United States, the main markets include Japan, South Korea, China and the European Union.
The Southern Shrimp Alliance, which represents shrimp fishermen and processors in eight U.S. states, won anti-dumping duties on imports from Brazil, China, Ecuador, India, Thailand and Vietnam in 2004 after a U.S. Commerce Department investigation found those countries guilty of unfair pricing practices.
That action helped stabilize an industry hit hard by plummeting prices. But annual U.S. administrative reviews have weakened the duties over the years and U.S. shrimpers are now struggling with historically low prices, the group's executive director, John Williams, told Reuters.
U.S. duties on shrimp from Thailand had such little effect that the Southern Shrimp Alliance recently negotiated a deal for the Thai shrimp industry to pay U.S. shrimpers at least $100 million to have the duties dropped, Williams said.
However, that agreement is opposed by a rival U.S. group, the American Shrimp Processors Association, which is urging the Commerce Department to block it, he said. (Additional reporting by Doug Palmer in Washington; Editing by Eric Beech)