* Firms call for net zero emissions well before century-end
* Say fighting climate change can bring economic benefits
* Want tough action from Paris U.N. summit in December (Updates with quotes from Kerry, Fabius, DSM)
By Alister Doyle and Geert De Clercq
PARIS, May 21 (Reuters) - Top European companies urged governments on Thursday to set a goal of slashing greenhouse gas emissions to net zero well before 2100, saying that going green can bring profits rather than costs.
Business leaders from global and European alliances of companies including Unilever, Total and Saint-Gobain also called for a global price on carbon emissions and a phase-out of fossil fuel subsidies.
"We want a global climate deal that achieves net zero emissions - make it happen," they said in a statement directed at almost 200 governments which are due to agree a deal to slow global warming at a summit in Paris from Nov. 30 to Dec. 11.
Net zero emissions would mean drastic cuts and imply any remaining emissions would be offset, for instance, by planting trees to soak up carbon dioxide or with yet-to-be-developed technologies to extract carbon from the air.
They said global emissions needed to peak around 2020 and reach net zero "well before the end of the century", matching advice from the U.N. panel of climate scientists, to give a good chance of limiting warming to manageable levels.
Organisers of the conference, part of efforts to build momentum for a global deal after past failures, said the statement was backed by 25 business networks representing more than 6.5 million firms in more than 130 countries.
Still, the Business and Climate Summit mainly attracted top European CEOs, while large U.S and Asian companies were notably absent.
The statement said businesses believed that a goal of net zero emissions was "compatible with continued economic growth".
"Business as usual is no longer possible," said Pierre-Andre de Chalendar, CEO of French building materials group Saint-Gobain.
Cuts in emissions can help avert economic damage from droughts, floods and rising seas, and have big benefits such as lowering air pollution that causes millions of deaths, especially in big emerging nations such as China and India, the U.N. panel says.
U.N. Secretary-General Ban Ki-moon, who has urged business involvement to help limit emissions, called the conference "an important milestone" on the way to the Paris summit.
U.S. Secretary of State John Kerry praised wider business involvement in cutting emissions. "Seize the opportunity," he said in a video message, for action that "will be felt not just in the boardroom and the factory floor but all across the planet".
French Foreign Minister Laurent Fabius said that he had a "strong but reasonable optimism" of a U.N. deal being reached in December, partly because both China and the United States were now committed.
"If the two great powers of the world, and the top two emitters, agree to go in the right direction, it makes it harder to go the wrong way," he said.
Even Saudi Arabian Oil Minister Ali Al-Naimi said OPEC's top producer was investing in solar power as it anticipates lower global reliance on fossil fuels.
"In Saudi Arabia, we recognise that eventually ... we are not going to need fossil fuels. I don't know when, in 2040, 2050 maybe," he told the conference.
Still, governments are sharply divided about whether to set a goal of net zero emissions at Paris, and whether the deadline should be 2050, 2100 or left open.
Feike Sijbesma, CEO of Dutch nutritional supplements maker DSM, told Reuters that future generations would suffer most from rising temperatures.
"In 2060, I will be dead, but my children not. If we do not act, the next generation will suffer tremendously, from droughts, flooding and infectious diseases."
(Additional reporting by Michel Rose and Jessica Chen; Editing by Ahmed Aboulenein and Pravin Char)
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