NEW YORK - Banks, pension funds and other investment groups representing more than $13 trillion in assets called for a strong global agreement on climate policy on Wednesday, saying it would lead to a flood of investment into the low-carbon economy.

Without the policies to encourage clean energy, investors are stuck at the starting gates, Mindy Lubber, the president of Ceres, a Boston-based coalition of investors and environmentalists, and the director of the Investor Network on Climate Risk.

More than 180 investor groups called for a global target of emissions reductions of 50 to 85 percent by 2050, including higher cuts by wealthy countries, and plans in developing countries to make measurable emissions reductions.

Many investors have complained that until climate policies are agreed upon it will be hard to finance and invest in billion dollar projects such as nuclear or natural gas-fired power plants.

The investors also called for revisions to the United Nation's Clean Development Mechanism, a Kyoto protocol program, that allows polluters in rich countries to claim emission cuts by investing in clean projects such as small hydropower and alternative energy in developing countries.

The call for action came ahead of a climate conference at the United Nations next week in which global leaders, including U.S. President Barack Obama and China's President Hu Jintao, are slated to talk about tackling climate change. The meeting is seen as a chance for leaders to break a deadlock between rich and poor countries on how to share the burden of cutting emissions blamed for global warming.

The gathering will come ahead of a U.N. meeting in Copenhagen in December where 190 countries aim to hammer out a new agreement to the Kyoto protocol, which expires in 2012.

In addition, the U.S. Senate hopes to pass its version of the climate bill that the House narrowly approved in June. The future of the bill is uncertain however.

Deep divisions between rich countries and rapidly developing ones such as China and India could keep a deal at Copenhagen at an arm's length.

Lubber said investors will keep up the pressure should the U.S. climate bill and global agreement fail this year.

The plan is to stay the course and try harder next year, should there be no deal, she said.

Nicholas Stern, a former British Treasury official and World Bank chief economist, said the fact that the leaders of the top two greenhouse polluters, China and the United States, were coming to next week's U.N. meeting was a sign of progress. He said the Copenhagen meeting could at least end with a basic framework of where to go in the future, if no deal is struck.

Several European banks were among the investor groups calling for climate action, but there were fewer U.S. banks. Lubber said the U.S. banks were not as far along as European banks in recognizing climate change risks but were beginning to catch up, because they recognize opportunities in investing in alternative energy and efficiency.

(Reporting by Timothy Gardner; Editing by Lisa Shumaker)