Germany’s Allianz SE, one of the world’s largest financial asset managers, said on Tuesday it would decrease investments in companies using coal and boost funding in those focused on wind power over the next six months.

Chief executive Oliver Baete said Allianz will no longer invest in companies if more than 30% percent of sales come from coal mining or if coal generates more than 30% percent of electricity.

He said Allianz decided ahead of next week’s United Nations climate change conference in France with “an eye on the 2C goal of the Paris climate negotiations as well as the economic risks involved.”

In 2014, Allianz managed about €1.8tn ($1.9tn) assets in US, Germany, France, Italy, Britain and the Asia-Pacific region.

The company plans to release more details later in the week, but experts estimate the decision on coal would affect investments worth €4bn. Some 90% of the investments affected are in bonds that will be allowed to mature while the six-month frame will apply to equities, Allianz said.

In Paris, more than 190 countries are to negotiate a new global pact to fight climate change. Most of them have already presented plans to cut greenhouse gas emissions after 2020, when the deal is supposed to take effect.

Environmental activist group 350.org applauded Allianz’s decision: “As the world’s largest insurance company, Allianz knows a thing or two about risk – and there’s no greater risk for the climate than continuing to invest in an industry that is wrecking the planet.”

The group said the company’s decision, and that of others, to divest from coal will weaken the fossil fuel industry’s political influence. “Decisions of large investors like Allianz, however, also hit the industry’s financial stability. It sends a clear signal to investors that the world is rapidly moving away from fossil fuels towards renewable energy.”

Allianz investment chief Andreas Gruber told ZDF television that the company’s decision was based on concern over global warming, but also because it made good financial sense.

He said the company is convinced climate-damaging investments won’t pay off in the future and said Allianz will double wind energy investments to €4bn. It expects a return of 5-6%.

“We want to support the negotiations at the climate summit in Paris in December, but also send a signal to our industry and the capital markets,” Gruber said.