Bangkok- The UN-sponsored climate change meeting in Bangkok fell behind schedule Friday on the failure to agree on timetables, sources said.

The plenary session of the five-day meeting, scheduled to start at 3 pm, was postponed by a few hours, although observers said talks should still be wrapped up by 10 pm.

Developed and developing nations at the meeting have disagreed on which topics should be prioritized at upcoming workshops on the main topics - mitigation, deforestation, technology transfer and finance.

"The developing countries want a certain order and the developed countries want another," said Bill Hare, of Greenpeace International.

"If they can't reach an agreement on a set of bloody workshops and papers it's a cock-up."

The Bangkok talks, coming three months after a landmark agreement was reached in Bali to set a road map for strengthening international action on climate change, has been tasked with setting the agenda for talks to be concluded next year on concrete plans to halt increases in global carbon emissions by 2015 and dramatically cut them by 2050.

This week's meeting was also working on rules for industrialized countries to meet their commitments under the Kyoto Protocol to cut carbon emissions within 10 to 15 years as the first real step toward slowing global warming.

"We have just one and a half years to complete negotiations on what will probably be the most complex international agreement that history has ever seen," said Yvo de Boer, executive secretary of the host UN Framework Convention on Climate Change.

Given the time constraints, many observers said they believed the most substantive outcome from the Bangkok talks would be an agreement to increase the number and length of of negotiations, which would require new financing.

The next major climate-change meeting is planned later this year in Poznan, Poland, and then the finale in Copenhagen in 2009. There will be several workshops between those two meetings.

The Bangkok talks drew about 1,200 delegates from 63 countries.