Five core members of the World Trade Organisation, under mounting pressure for a deal on farm trade reform, will meet in Paris next week ahead of a ministerial gathering, diplomats said on Tuesday.
Trade officials and diplomats from the United States, the European Union, Australia, Brazil and India, will meet on May 12 and 13 to try to tackle complex technical issues which must be settled if ministers are to decide anything, they said.
"If we cannot deliver anything before the Paris ministerial meeting, then we could have a problem on our hands," said one Geneva diplomat who will attend the talks.
A US presidential election in November and a new team taking over at the European Union's executive Commission in the autumn means there is little chance for any further negotiation this year if a summer deadline is missed, diplomats say.
The WTO has set itself a summer deadline for accords on freeing up trade in farm and industrial goods. Diplomats say agriculture poses the tougher obstacle to completing an overall WTO trade agreement initially promised for the end of 2004.
The July timetable is for outline deals, known as frameworks at the WTO, which would set down the boundaries and criteria on which final accords could be based, but leave the detail to be dealt with later, probably next year.
The Organisation for Economic Co-operation and Development has invited trade ministers from 28 countries to Paris on May 13 and 14 for what could be the last chance to get so many top officials together before the summer.
Diplomats said the technical talks would focus on lowering barriers to agricultural imports, which is proving one of the biggest stumbling blocks.
The European Union and the United States favour a "blended" formula, which would allow the EU and countries like Japan with expensive domestic farm industries to keep high tariffs on some politically sensitive goods.
But leading farm goods exporters such as Australia and Brazil say that would be too soft on rich states and too hard on developing countries.
The United States has set better access to potentially lucrative markets in developing states like India as a condition for cutting its lavish farm subsidies, which critics blame for distorting world markets.
Any deal would still only be a small step towards completing the WTO's Doha Round of trade liberalisation. The round was supposed to be finished by end-2004, but trade officials said long ago that that target would be missed.