The campaign to sell off investments in fossil fuel projects, particularly those involving coal, is no longer a fringe movement as big players like banks and investment funds get on board.

The divestment campaign has come a long way from its beginnings in the United States, where students began pressuring their university investment funds in 2008 to pull their money out of companies connected with fossil fuels.

Norway decided in June to pull its sovereign wealth fund -- the world's biggest -- out of coal and many advanced nations agreed earlier this month to restrict subsidies that help companies export coal-fired power plants.

Financial institutions have also joined up, to varying degrees, such as insurers Axa and Allianz, as well as banks like Bank of America Merrill Lynch, BNP Paribas and Societe Generale.

"The world of finance has begun to move on climate," French Foreign Minister Laurent Fabius, who presides over the Paris conference on climate warming that opens on Monday, told AFP in an interview earlier this year.

Even Standard and Poor's has begun to take account of climate change risks in its credit ratings.

"You can clearly see that it is beginning to get a bit worrying for banks to not take it into account," said Pierre Forestier, who heads the climate change section at AFD, France's development agency.

He says that for the past two to three years "there has been a real trend and it is no longer just greenwashing", or a marketing effort designed to give an impression a company is concerned about the environment.

- $50 billion divested -

And divestment doesn't mean losing money, according to an analysis by activist groups Corporate Knights, 350.org and South Pole Group.

Their examination of 14 major funds with a collective $1 trillion in assets found they would have earned $22 billion more if they had shifted out of fossil fuels into clean energy stocks three years ago.

"Contrary to the conventional wisdom, divesting from fossil fuels in favour of clean energy has been a huge money-maker," Corporate Knights said on its website.

According to the "Go Fossil Free" campaign launched by 350.org, $50 billion has been divested from fossil fuels worldwide.

A study by consultancy Arabella Advisors released in September found that 436 institutions and 2,040 people worth a total of $2.6 trillion had pledged to get out of fossil fuels, either entirely or in certain sectors such as coal.

Novethic, a research outfit dedicated to responsible investment that is a subsidiary of France's state investment bank, the Caisse des Depots, said that more and more of the companies that it surveys have decided to divest.

The number rose by a third between July and October, with just over half now planning to exit fossil fuels.

However Novethic's director Anne-Catherine Husson-Traore noted that "there are geographical areas where it is easier to get out of coal than others."

Forestier agreed. Divestment is just "the first step", he said.

"The question isn't just about getting out of coal, but also bringing about a complete change and ending our total dependence on fossil fuels."