2010-04-12BONN/LONDON (Reuters) - Delegates from 175-nations agreed on two extra sessions of U.N. climate control talks this year at the end of a tortuous meeting in Bonn that presaged big battles ahead over the non-binding Copenhagen Accord.

The Copenhagen Accord seeks to limit a rise in average world temperatures to below 2 degrees Celsius (3.6 F) over pre-industrial times but does not spell out how.

Reached at a fractious U.N. climate summit in December, the accord was strongly backed by Washington and bitterly opposed by some developing nations, though it also holds out the prospect of $100 billion climate aid a year from 2020.

"This process has big problems," said Annie Petsonk of the U.S.-based Environmental Defense Fund, at the end of the meeting in Bonn.

The session had been due to end on Sunday, but delegates wrangled deep into the night over a two-page plan to guide negotiations, with several hours spent on the wording of what appeared to be uncontroversial phrases.

The final text skirted one of the biggest problems -- the fate of the Copenhagen Accord. The December summit had disappointed many by failing to come up with a binding treaty.

"We have just about worked out the procedural kinks -- save the big one, which is what to do about the way in which we will respond to the Copenhagen Accord," Dessima Williams of Grenada, chair of the Alliance of Small Island States, told Reuters.

The accord was not mentioned by name in the Bonn workplan.

Margaret Mukahanana-Sangarwe of Zimbabwe, who chaired the U.N. talks and will draw up new draft texts by May 17, said the phrasing had a "constructive ambiguity...to me it seems to cover the work that was done to produce the Copenhagen Accord."

The Accord has backing from almost 120 of 194 member states, including top emitters China, the United States, the European Union, Russia and India.

It faces opposition led by countries such as Bolivia, Cuba, Sudan, Saudi Arabia and Venezuela.

Some developing nations complained that rich countries pledged insufficient action under the Accord to stop disaster for millions of people from floods, droughts, heatwaves and rising seas.

By contrast, Saudi Arabia fears a shift from oil to renewable energies.

Bolivia said that the Bonn meeting had ruled the Accord out of negotiations that will culminate in a ministerial meeting in Mexico in November and December.

"Despite continual attempts by the U.S. to make the completely unacceptable Copenhagen Accord the basis for future negotiations, I am glad to say they failed," said Pablo Solon, Bolivia's chief delegate.

The U.N.'s top climate official, Yvo de Boer, said he did not expect a breakthrough to achieve a new treaty in Mexico.

For a $125 billion carbon market, failure to agree a global legally binding deal would be "regrettable" but tough national policies were more important, said one expert.

"It is cap and trade which is driving this market," said Andrei Marcu, head of regulatory and policy affairs at oil trading firm Mercuria.

Cap and trade schemes control industrial carbon emissions by forcing companies to buy from a fixed quota of emissions permits.

A European scheme is at the centre of a carbon market which could grow significantly if the United States passes a climate bill this year.

"I'm looking very much to what the U.S. will do," said Marcu, who was upbeat that the Bonn meeting had re-launched talks which "fell apart" in Copenhagen.