* Brown to become policy adviser to World Economic Forum
* Currently mooted as next IMF chief
GENEVA, April 22 (Reuters) - Former British prime minister Gordon Brown is to take an unpaid post as adviser to the World Economic Forum (WEF), the Swiss-based body which organises the annual global leaders' meeting in Davos said on Friday.
The former leader of the now opposition Labour Party headed the British government from 2007 until he lost power in an election last year. He is also mooted as the next managing director of the International Monetary Fund (IMF).
The WEF said Brown would be chairman of a new "policy and initiatives coordination board", bringing together heads of international organisations and government officials to assess priorities for the world economic system.
Brown, who was Britain's Chancellor of the Exchequer -- or finance minister -- from 1997 to 2007 under the government of his Labour predecessor Tony Blair, has in the past been a keynote speaker at Davos meetings.
Klaus Schwab, founder and executive chairman of the WEF, said Brown would bring a wealth of knowledge to the organisation.
"His counsel will help ensure that the forum remains rigorous and focused -- true to its commitment to improve the state of the world," said Schwab.
Foreign commentators have said Brown is a strong candidate to take over at the Washington-based IMF if its current chief, Dominique Strauss-Kahn steps down to run for the French presidency next year.
But Britain's Conservative Prime Minister David Cameron, who heads a coalition government with the Liberal Democrats, said this week Brown was not the right person for the job and the IMF should look beyond Europe for candidates.
Cameron, whose stance could bar his predecessor from the IMF post, blames Brown for what he says was the economic mess his government inherited.
Brown's defenders say he did as good a job as could be expected in steering Britain through the global economic crisis of 2008-09 and also launched initiatives that ensured the international banking system would not collapse. (Editing by Sophie Hares)