BONN, Germany (AP) — A Norwegian investment fund that manages assets worth over $80 billion is pulling investments from ten companies over their involvement in the coal sector.

Storebrand, Norway's biggest private pension provider, says it divested from companies including German energy company RWE, Poland's PGE and Eskom Holdings of South Africa.

Its chief executive, Jan Erik Saugestad, said Thursday the decision is meant as a warning to utility companies to "clean up" their energy sources "or lose customers and investors."

Storebrand said it hopes the much larger Norwegian Sovereign Wealth fund, which holds $1 trillion generated from the country's sale of oil, will follow its divestment decision.

The move comes as over half a dozen countries attending global climate talks in Bonn, Germany, announce an alliance on phasing out the use of coal.