Thailand has welcomed a World Trade Organisation (WTO) ruling upholding a decision which found against United States anti-dumping duties imposed on shrimp exports to the US.

US taxes imposed on shrimp imports from Thailand and India break international trade rules, the WTO ruled on Wednesday, rejecting a US appeal.

The global commerce referee upheld a decision it issued in February.

The US imposes anti-dumping taxes when it believes its markets are being flooded with below-cost imports.

Washington insists it calculates the taxes fairly, but the WTO has consistently ruled that the US excessively taxes foreign goods it suspects are being dumped.

Deputy Prime Minister and Commerce Minister Mingkwan Sangsuwan welcomed the WTO's decision, saying the ruling would help frozen shrimp exports to the US, hit by the anti-dumping tax since 2003.

Thailand and the US would now negotiate over import tariffs, including the anti-dumping duty, on Thai frozen shrimp, which stand at 5.29-6.82%.

Thailand will also ask the US to return a guarantee fund, called the Continuous Bond (C-Bond), worth more than 12 billion baht which Thai exporters paid to get access to the US market.

Shrimp exporters who want to export to the US are required to pledge the guarantee, as part of US anti-dumping measures.

Mr Mingkwan said the Thai shrimp industry would now regain strength. Half the country's total exports, valued at 80 billion baht a year, goes to the US market, followed by Japan (17%), European countries (9%) and Canada (7%).