A group of seven ministers negotiated hard into the early hours of yesterday morning to break the World Trade Organisation deadlock, but the much-need breakthrough remains elusive, with key countries still far apart on some crucial issues.

The seven ministers and their officials were part of what WTO Director General Pascal Lamy has called the "variable geometry" of the talks.

It is a change in direction in the talks that has flowed from the slower progress in the 'Green Room' meetings of about 30 countries.

But even if a breakthrough was reached by this group of seven, Mr Lamy said that whatever was agreed would still have to go through the larger groupings such as the Green Room and eventually the full membership.

The ministers' consultations ended at 3.30 am and Mr Lamy said they genuinely shared a desire to bridge differences.

The discussion was intensive, detailed and specific "involving numbers and a clear enunciation of possibilities and problem areas".

In agriculture the focus continued to be on: overall trade-distorting domestic support for developed countries; cotton; top-tier tariff cuts for developed countries; sensitive products, which will be shielded from full tariff cuts in return for some market access through quotas with lower tariffs; developing countries' special products which will also be shielded from full tariff cuts; and temporary increases in developing country tariffs to deal with import surges or price slumps — the 'special safeguard mechanism'.

On some of these issues, "positions still remain too far apart", Mr Lamy said.

"The priorities among these issues vary among delegations, but I think all agree that more work is needed overall.

"These issues are both technically and politically complex."

The seven delegations were due to meet again today (Australian time), the fourth day of the meetings involving ministers.

"I believe the prize is within sight, and we must not fail to claim it," Mr Lamy said.

"What's on the table is already potentially major progress."

However, several members told the WTO meeting they were concerned that the negotiations now involved only seven members.

They said they understood the need for consultations in small groups, but the seven could not properly represent them and lack of information about the discussion meant that even some group coordinators could not brief their coalitions.

They cautioned that this could jeopardise the "transparent" and "inclusive" principles of the negotiations process and deprive members of ownership of the outcome.

"This problem exists," Mr Lamy conceded.

"Ownership is a problem, but there is a bigger problem if there is nothing to own."

He added that he had already scheduled briefing sessions with some coalition coordinators so that they in turn could keep the members of their groups informed.