OSLO (Reuters) - More than 110 countries have signed up to the Copenhagen Accord on fighting global warming but the United Nations said on Wednesday that their pledges for cutting greenhouse gas emissions were insufficient.

The first formal U.N. list of backers of the deal, compiled since the text was agreed at an acrimonious 194-nation summit in December, showed support from all top emitters led by China, the United States, the European Union, Russia, India and Japan.

It also includes smaller emitters from Albania to Zambia.

The accord, which falls short of a binding treaty sought by many nations, sets a goal of limiting global warming to below 2 degrees Celsius (3.6 Fahrenheit) above pre-industrial times. But it leaves each nation to set its own targets for 2020.

Yvo de Boer, outgoing head of the U.N. Climate Change Secretariat which compiled the list, said pledges for cutting greenhouse gas emissions so far fell short of that goal.

"It is clear that while the pledges on the table are an important step towards the objective of limiting growth of emissions, they will not in themselves suffice to limit warming to below 2 degrees Celsius," he said in a statement.

The accord also outlines almost $10 billion a year in aid for poor nations from 2010-12, rising to at least $100 billion from 2020, to help them slow emissions growth and cope with impacts such as floods, droughts and rising sea levels.

MEXICO

De Boer said the accord could be used to help advance formal negotiations towards a successful outcome in Mexico, which will stage the next U.N. climate conference of the world's environment ministers in Cancun in late 2010.

Many experts, including de Boer, have expressed doubts that Mexico will achieve a breakthrough where Copenhagen failed to work out a U.N. pact to succeed the existing Kyoto Protocol. One reason is that U.S. carbon capping legislation is stalled.

The Secretariat said that 112 parties -- 111 nations and the European Union -- had so far signed up for the accord. The list of 111 includes the 27 individual EU states.

It said 41 rich nations submitted goals to cut greenhouse gas emissions by 2020 and 35 developing countries outlined plans to limit growth of emissions. Together they account for more than 80 percent of world emissions from energy use.

The Copenhagen Accord was merely "noted" by the 194-nation summit after objections by a handful of developing nations including Venezuela, Nicaragua, Cuba and Sudan. The United Nations then asked all countries to say if they wanted to be listed or not. Wednesday's list is the result.

Many emerging economies were initially reluctant to sign up after the deal failed to gain universal support, even though the original text was worked out by U.S. President Barack Obama with leaders of states such as China, India, Brazil and South Africa.

Many developing nations want the 1992 U.N. Climate Convention to guide U.N. negotiations on a new treaty, arguing that it spells out more clearly that rich nations must take the lead. Washington, by contrast, favours the Copenhagen Accord.

Nations that stayed off the list include many OPEC countries such as Saudi Arabia, which fears a loss of oil revenues if the world shifts to renewable energies, and some small island states such as Tuvalu which fear rising sea levels.