Tough curbs on fishing subsidies have been proposed as part of an eventual global trade agreement, according to draft changes to World Trade Organisation subsidy and anti-dumping rules.

Environmental groups hailed the new proposals to scrap billions of dollars paid out in subsidies to fishing fleets as the single biggest opportunity to save endangered fish stocks.

Washington, however, said it was “very disappointed” with separate proposals by Guillermo Valles Galmés, the Uruguayan ambassador chairing the WTO negotiations, which would tighten curbs on nations’ use of anti-dumping measures.

WTO members agreed on Friday to aim to conclude the much-delayed Doha round of world trade talks by the end of next year.

The US has insisted that any change to WTO anti-dumping rules must permit a practice known as “zeroing” which, critics say, inflates dumping margins and the duties based on them. Zeroing has already been condemned in several WTO dispute rulings – mostly against the US.

While Mr Valles Galmés’s draft text allows “zeroing” in certain circumstances, it does not go as far as the US wants and it includes a number of measures that would make imposing and maintaining anti-dumping duties more difficult.

The proposals on fishing subsidies – estimated to be at least $20bn (€13.7bn, £9.7bn) annually – are more to Washington’s liking. But the European Union and Japan, the world’s biggest subsidisers, are expected to try to water them down.

The proposals would eliminate most subsidies to fleets by rich nations. Developing countries would be allowed to provide some subsidies, but only if they operated an internationally recognised fish-stock management programme. The very poorest states would be exempt.