Thailand has filed a complaint with the World Trade Organisation over US anti-dumping duties on its shrimp exports, claiming US procedures for calculating the duties violate WTO rules.

The complaint follows a US Commerce Department decision last July to impose provisional duties of 5.56-10.25 per cent on shrimp imports from Thailand, by far the largest shrimp exporter to the US with sales worth nearly $1bn (€745m, £515m) last year. Duties were also imposed on shrimp imports from Brazil, Ecuador and India. A decision on final US dumping duties for the four countries is due on December 20. Two weeks ago the US Commerce Department issued final determinations for shrimp imports from China and Vietnam, of 113 per cent and 26 per cent respectively. Frances Williams, Geneva