The plan, drawn up by Uruguayan Ambassador Carlos Perez del Castillo, with the backing of World Trade Organization (WTO) chief Supachai Panitchpakdi, seeks to bridge wide gaps, not just between developed and developing states but also within the two camps, on issues ranging from farm reform to industrial tariffs and services.

Calling the plan "flawed", several trade envoys said it could serve as a basis for further negotiations at a crucial ministerial meeting in Cancun, Mexico, next month, providing the proposal was modified.

"It is flawed, but not fundamentally flawed," said European Union chief negotiator Peter Carl. "It is unbalanced."

A spokesman for the US Trade Representative's office in Washington said Perez del Castillo's draft hit the mark in some areas, but missed it in others.

"We will continue to work with the chairman as he develops a package for ministerial consideration," USTR spokesman Richard Mills said. "We maintain a high level of ambition in the key areas of negotiation, particularly agriculture, which is at the heart of the Doha agenda and the key to development."

Agricultural reform is central to WTO negotiations on lowering barriers to trade across the globe, but disagreements still run deep just two weeks before the Sept 10-14 gathering that could decide the fate of the Doha Round of free trade talks.

"The great majority (of countries exporting agricultural products) are disappointed with this document. There is a great deal of frustration," said one trade envoy from a Latin American country.

But Perez del Castillo, who put forward his blueprint after two weeks of intense negotiations in Geneva, warned that there was little time for further revisions before the Mexican summit.

"This text goes as far as I judge is possible in the Geneva process," he said, referring to the latest round of talks in the Swiss city.