* Fund is world's largest sovereign wealth fund
* Fund has ethical ambitions
* First coal divestments were in 2015
* Graphic of largest SWFs: http://tmsnrt.rs/2tskfub (Updates with passing into law, updates comments in last paragraph)
By Gwladys Fouche
OSLO, June 12 (Reuters) - Norway's $1 trillion sovereign wealth fund may have to sell a $1 billion stake in commodities firm Glencore and other investments to meet tighter ethical investing rules adopted by its parliament.
Norway's parliament agreed on Wednesday to the centre-right government's plan that the world's largest fund would no longer invest in companies that mine more than 20 million tonnes of coal annually or generate more than 10 gigawatts (GW) of power from coal.
Environmental campaigners Greenpeace and Urgewald said the new rules mean the fund would have to divest its 2.03% stake in Glencore, worth $1 billion at the end of 2018 according to fund data.
The fund would also have to sell its 2.16% holding in miner Anglo American, worth $620 million, they added, citing their own analysis.
The fund, Glencore and Anglo American all declined to comment.
"What this does do ... is give a very clear signal to both governments and companies that the time for financing fossil fuels is coming to an end, for the benefit of both people and planet," said Martin Norman, Sustainable Finance Campaigner at Greenpeace in Norway.
Other divestments would include the fund's 1.39% stake in Germany's RWE worth $186 million, its 2.22% holding in Australia's South32 worth $266 million and the 1.03% it owns in Germany's Uniper among others, the green campaigners said.
The original rules on investing in coal, also set by parliament, called for the fund not to invest in a company that derived more than 30 percent of its revenues from coal.
That led the fund to sell its stakes in 83 mostly coal-producing companies, such as Peabody Energy and Coal India, as well as power producers ranging from Portland General Electric to Korea Electric Power .
It was the first major fund to do so and those divestments in 2015 prompted other long-term investors to set similar guidelines, including German insurer Allianz later that year.
Uniper said its generation capacity globally was less than one third coal-based, adding that it aims to use more low-carbon fuels and had already cut its carbon dioxide emissions by some 20% since 2016.
"We see ourselves as partners in the energy transition and want to accompany it constructively," a Uniper spokeswoman said.
RWE said its transformation plan includes not building any new coal-fired power plants, and it added that it will invest up to 1.5 billion euros ($1.70 billion) annually in new renewable energy projects once its transaction with EON is completed.
"By the end of 2019, more than 60% of RWE's plants will be able to supply electricity with little or no CO2 emissions," a spokeswoman said.
South32 and BHP Billiton declined to comment while Enel did not reply to a request for comment. ($1 = 0.8821 euros)
(Reporting by Gwladys Fouche, editing by Louise Heavens and Elaine Hardcastle)
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