AEP said Thursday it will assess and report to its shareholders the potential impact of the company's actions to improve the environmental performance of its power plants. And AEP said it will keep those coal-burning power plants cost-competitive.

Last year a shareholder resolution urging AEP to cut its emissions of greenhouse gases and several air pollutants won a surprising 26.9 percent of investor votes.

This year the shareholders withdrew their proposal and negotiated an agreement with AEP.

A subcommittee of independent directors from AEP's board will assess the impacts of and potential responses to several regulatory proposals to limit carbon dioxide and other emissions.

AEP officials said the shareholders' request for an emissions assessment was reasonable.

The Coalition for Environmentally Responsible Economies said the resolution focuses on the financial risks to shareholders posed by the company's emission of carbon dioxide. As the world becomes more concerned about global warming, some suggest it is likely that carbon dioxide emissions will be regulated in the United States. As AEP is the largest emitter of carbon dioxide in the nation, then real cost becomes a factor for AEP, said Nicole St. Clair, spokeswoman for CERES.

Prudent management of investments means identifying these risks and moving to mitigate them. And that includes disclosure of the company's risks and plans to avert them, St. Clair said.

Mindy Lubber, CERES executive director, said in a statement, "This is an historic breakthrough for shareholders who care about corporate governance and good disclosure of long-term risks to their investments."

The agreements come on the heels of increasing pressure on the electric power industry to address the issue of coming carbon dioxide constraints, CERES said.

Given that AEP cut its dividends to 35 cents from 60 cents for the second quarter last year because of poor financial results, AEP officials said it would be irresponsible to shareholders for it to spend to cut emissions beyond what was required by law, the Wall Street Journal reported last year.

AEP will post its report Sept. 1 on its Web site, www.aep.com, and will make it available to shareholders upon request.