Uncertainty surrounds an April 30 target for an accord on cutting tariffs on industrial and agricultural goods, as well as slashing subsidies paid to farmers in rich nations which critics say undermine competitors in the developing world.
The lack of progress means that the WTO has still not decided whether to hold a meeting of trade ministers at the end of this month to cap weeks of talks among specialised negotiators.
The spotlight remains on trade diplomats in Geneva this week who are attempting to break the deadlock which pits the rich, notably the European Union and United States, against developing country powerhouses including Brazil and India.
"Everthing depends on the discussions in the next three days. If we are recording significant convergence on the 21st, I expect (WTO Director General Pascal Lamy) to decide to have this ministerial meeting or not," Ujal Singh Bhatia, India's trade ambassador, told AFP.
The April 30 deadline was part of a loose agreement at a WTO conference last December in Hong Kong.
At the conference, governments tried to bring some momentum back to the struggling Doha Round of negotiations, which was launched in 2001 with the aim of tearing down barriers to commerce and using trade to boost the economies of poor nations.
WTO members have missed several previous deadlines: the Doha Round was originally meant to end in 2004.
This month's target is part of a drive to complete the round by the end of the year, before Washington loses its special negotiating powers in 2007 and the US Congress gets back the power to pick apart any deal, potentially complicating future talks.
In Hong Kong, governments agreed that they would reach a deal on "modalities" -- WTO jargon for formulas and other guidelines for reducing trade barriers.
Despite some steps forward, governments and their negotiators have been unable to agree on the mathematics for the highly technical and politically charged formulas.
In the WTO agriculture talks, the EU and US have been under pressure from developing countries led by Brazil and India, as well as rich farm exporters including Australia, Canada and New Zealand, to make more concessions on tariffs.
The EU and US, as well as other rich WTO members, are seeking more access to developing world markets for their industrial goods and services such as banking.
Some developing countries are also pushing for freer trade in services: New Delhi is pressing for Indian information technology experts to be able to do business easily in person in rich countries.
Other poor nations, particularly former European colonies with preferential trade deals with the EU, are worried about losing out on a more level playing field.
"Everything is on the table now, but in agriculture the complexity of the issues which still remain to be resolved is immense," said Bhatia.
"Depending on how much ambition there is in the developed countries' market access we will then discuss developing countries' contribution."
Brazilian Foreign Minister Celso Amorim recently said that he was pessimistic about the April 30 deadline.
"Without a strong gesture soon, I don't see anything at present which would enable an agreement," he said last week.
On Tuesday EU Trade Commissioner Peter Mandelson said that a "dose of realism" was needed in the talks.
"I would like to say that we are going to meet our deadline ... but I fear it will be very difficult because the differences are still too wide," he said in an interview published in the Financial Times.
Beyond the looming deadline, governments face a July 31 target for "schedules" -- details of how they would implement a final trade deal.
Bhatia said that missing this month's goal would be "serious but not fatal."
"The situation can still be redeemed if we can finalise the structure before summer," he said.
Lamy could try the option of drafting a deal himself, repeating the controversial 1991 move by Arthur Dunkel, a previous global trade chief, which ultimately broke a logjam in talks.
But in an interview Tuesday in the Wall Street Journal, Lamy said that would be a "last gasp."
"It's something that's very dangerous. It's an extreme step," he said.