DETROIT -- Environmentalists are claiming victory following General Motors Corp.'s decision to quit a lobbying group that has led the opposition to a 1997 global warming treaty reached in Kyoto, Japan.

Ford Motor Co. and DaimlerChrysler Corp. withdrew earlier.

GM notified the Washington-based Global Climate Coalition on Monday that it was ending its membership, GM spokesman Bill Noack said Tuesday.

''GM's withdrawal ... makes me hopeful that opposition to real solutions is in permanent decline,'' said John Passacantando, executive director of Ozone Action.

''As the impacts of global warming worsen, it will take increasing moral maturity on the part of our corporations and country to rise to the occasion,'' said Sister Patricia Daly of the Interfaith Center on Corporate Responsibility. ''General Motors' departure from the global warming skeptics is a step towards achieving this maturity.''

GM remains opposed to the Kyoto agreement but acknowledges that carbon dioxide buildup in the atmosphere could be changing the world's climate.

The withdrawal ''really doesn't reflect any change in our position,'' Noack said from Washington. ''We continue to oppose the Kyoto Protocol.''

After the GM announcement, coalition Executive Director Glenn Kelly said the group was restructuring and individual companies no longer could join. Instead, he said membership would consist only of trade associations.

Many scientists believe Earth is gradually warming because of greenhouse gas emissions -- mainly carbon dioxide from automobiles, factories and power plants.

If ratified by the U.S. Senate, the climate treaty would require that the United States reduce greenhouse emissions to below 1990 levels by 2008-2012.

Noack said the decision to leave the coalition was a strategic one.

''Our company has taken more of a global focus,'' he said.

Ford quit the coalition in December, and DaimlerChrysler followed in January.

When it left, DaimlerChrysler cited possible evidence of global warming. Ford said the coalition had become an impediment to pursuing environmental initiatives in a credible way.

Other major companies that have left the group include British Petroleum, Shell Oil and Dow Chemical.

In its statement, the Global Climate Coalition said its reorganization was ''part of a long-term initiative to refocus the public debate on climate policy to the issues at hand - namely, a policy contest between the unworkable Kyoto Protocol versus a more pragmatic and viable solution to the climate issue that relies on technology, innovation and American ingenuity.''

The Kyoto treaty would not impose limits on economically developing countries such as China and India. Automakers and the coalition have said that because those countries account for a significant portion of the world's population, and therefore its pollution, they also must agree to emissions cuts.

Kelly said prospects for the Kyoto treaty look increasingly bleak, and the coalition believes the best course is one that emphasizes technology-based solutions to the climate question.

''We're eager under our new structure to continue working with the Congress, the administration, and others to continue advancing those solutions,'' he said.