PORT OF SPAIN (Reuters) - British Prime Minister Gordon Brown called Friday for the creation of a $10 billion a year fund to help developing countries battle climate change.

Britain's Prime Minister Gordon Brown arrives for the official opening ceremony of the Commonwealth Heads of Government Meeting (CHOGM) at Port of Spain in Trinidad November 27, 2009. REUTERS/Toby Melville

Brown made the proposal as Commonwealth leaders met to try to build momentum for an agreement in global climate talks in Copenhagen next month.

Under Brown’s proposal, funds could be made available to poor countries as early as next year, well before any new climate deal takes effect.

The European Union has already looked at similar proposals for “fast-start” financing but has so far been unable to agree on a figure.

“What I feel the developing countries need to know is that we are absolutely serious that we would start now” to provide financing, Brown told a news conference on the sidelines of the summit in Trinidad and Tobago.

“What I’m proposing today is a Copenhagen launch fund. It would start in 2010. It would be $10 billion per annum by 2012,” he said.

The 53-nation Commonwealth brings together wealthy and developing countries.

Brown believes the fund would give the developing world greater confidence that rich countries would give them financial support and so encourage them to act to counter climate change.

The fund would run from 2010 to 2012, increasing to $10 billion in the final year, under Brown’s plan. Brown aides could not say how big the fund would be in the first two years.

Britain is prepared to contribute 800 million pounds ($1.31 billion) -- already set aside in Britain’s budget -- over three years to the fund, officials said.

Brown said he believed the EU and the United States would also be ready to contribute to the fund.

EU leaders said last month that developing countries will need 100 billion euros ($149 billion) a year by 2020 to battle climate change.

Brown said half of the money in his proposed launch fund should go toward helping the poorest countries adapt to climate change, by for example financing stronger sea and flood defenses.

The other half would help countries deal with deforestation and building new, cleaner energy sources.

Developing countries would have to provide part of the finance for projects to lessen the impact of climate change and payment from the fund would depend on results.

“The more carbon you reduce, the more tons of greenhouse gas saved, the more money any developing country would get from that fund,” Brown said.