UNITED NATIONS-U.S. institutional investors pledged at a UN summit yesterday to invest $10 billion over two years in technologies that aim to reduce greenhouse gas emissions and to pressure companies to disclose their risks associated with climate change.

The plan "reflects the many investment opportunities that exist today to put a dent in global warming pollution, build profits and benefit the global economy," said Mindy Lubber, the president of Ceres, a coalition of investors and environmental leaders, and director of the Investor Network on Climate Risk.

Hundreds of investors controlling $20 trillion in capital came to the summit searching for answers on how to put a price on carbon emissions blamed for global warming and create a new - and lucrative - economy based on cleaner sources of energy.

Business leaders asked how they could blunt the economic cost of cutting carbon emissions - chiefly carbon dioxide from burning oil, coal or natural gas - when cheap and carbon-intensive energy is powering growth around the globe.

"As soon as people believe carbon has a price, it's going to have a price," said Vinod Khosla, a venture capitalist who was one of the co-founders of Sun Microsystems.

Peter Darbee, chairman and CEO of PG&E Corp., an energy-based company in San Francisco, said cleaner-burning utilities should be rewarded and "those that burn coal should have to pay for clean energy.''

The gathering of 480 investors and other Wall Street types was organized by groups supporting UN efforts such as the UN Foundation, Ceres and the UN Fund for International Partnerships.

Lubber called it the largest meeting of financial leaders ever to focus on climate change and said it would illustrate how the marketplace is starting to transform.

"Investors will be looking at clean energy opportunities, including energy efficiency, as Wall Street wakes up to the scale of the climate challenge and what actions it will require," she said.

Former U.S. vice-president Al Gore advised meeting attendees to ditch businesses too reliant on carbon-intensive energy or prepare for huge losses down the road.

"You need to really scrub your investment portfolios, because I guarantee you - as my long-time good redneck friends in Tennessee say, I guaran-damn-tee you - that if you really take a fine-tooth comb and go through your portfolios, many of you are going to find them chock-full of subprime carbon assets," Gore said.