The local shrimp industry said its survival could depend on a favourable ruling by the World Trade Organisation (WTO), after the body launched a formal investigation on Thursday into US anti-dumping duties on shrimp imports from Thailand.

Somsak Paneetatyasai, president of the Thai Shrimp Association, said yesterday he hoped the WTO would urge the US to end its "continuous bond" on Thai shrimp imports.

"Based on our information, we've gained the upper hand, because the redundant tax collection violates WTO rules," he said.

Exporters say the US regulations are devastating the local shrimp industry because of increasing costs of production.

Somsak said that normally the WTO should take eight months to one year to hear the case.

The United States blocked Thailand's first request for the WTO to set up an investigative panel in September. Under WTO rules, a panel is established automatically with the second request.

India made its first request for a panel to deal with a similar claim at the meeting of the WTO's Dispute Settlement Body on Thursday, but it was also blocked by the US, a WTO official said.

A Thai representative told the meeting said the US imposition of a continuous bond requirement, as well as another tariff measure, were "endangering the livelihood of

our shrimp farmers and the existence of our recovering shrimp industry".

The US said it was disappointed that Thailand had chosen to bring its case to the WTO because "members have the right to ensure that importers pay duties owed".

In Geneva, US negotiator David Shark told the Dispute Settlement Body that Washington was confident the panel would "recognise this fact and reject Thailand's claims".

Governments impose anti-dumping duties when they suspect that producers are exporting products at below the market price in their own country.

Thailand says the import duties threaten the livelihood and sustainability of its industry because the US is its largest market and accounts for half of its exports.

The shrimp industry employs about one million people, many of whom are still repaying huge debt incurred after the 2004 tsunami.

Thailand has argued that the US improperly calculates anti-dumping fees through a complicated procedure for determining tariff rates known as "zeroing". It also has said the procedures for paying the levies were overly cumbersome.

Previous WTO panels have found that zeroing leads to artificial and inflated margins of dumping, and thus higher duties. But arbiters largely sided with the US last month in a zeroing dispute initiated by Japan, saying most of the examples cited by Tokyo of alleged wrongdoing did not violate international rules.  

The US also has anti-dumping duties on shrimp imports from Brazil, China, Ecuador, India and Vietnam.