Tim Groser, New Zealand's ambassador to the WTO who is chairing the three days of consultations, said there were signs of a desire to devise a framework for agriculture negotiations by July 31. But he warned participants against holding back until the last minute.

Many countries feel that market access for farm products is the hardest hurdle to overcome, with poor countries demanding an end to the subsidies given to farmers by rich states while developed nations oppose the high tariffs slapped on goods by their less-developed trading partners.

The tricky issue helped to derail the latest round of trade talks at a ministerial meeting in Cancun, Mexico last year.

Negotiations, which have only recently restarted, are due to finish by January 1, 2005, but success largely hinges on whether an agreement can be reached on agriculture.

The talks, aimed at tearing down global trade barriers, are part of the Doha round of negotiations that was launched in the Qatari capital in November 2001.

At a meeting of the agricultural negotiating committee at the WTO's headquarters in Geneva, three groups -- the self-named G20, G10 and G33 -- presented their proposals. Member states then broke into smaller discussion circles and are due to regroup on Friday to discuss any progress that is made.

The Group of 20 developing countries (G20), which include Brazil, China and India, proposed a progressive formula for reducing farm tariffs that would impose sharper reductions in the higher farm tariffs.

The G20 devised its plan after rejecting a "blended" formula proposed last August by the European Union and the United States that combined an average tariff reduction with a sharper cut on certain higher tariffs.

According to the latest draft, flexibility would be allowed on the most sensitive products -- such as rice, which carries a 500 percent tariff in Japan -- on condition that the countries involved lower their tariffs and establish minimum import quotas for such products.

"Tariffs shall be capped, with possible exceptions for a very limited number of products on conditions to be agreed," the G20 said.