PROVIDENCE, R.I. – A regional effort that would require power plants in the Northeast to reduce carbon dioxide emissions is still in the working stages, with no final agreement imminent, a participant said.

The Regional Greenhouse Gas Initiative has been working since 2003 on what would be the first multistate plan in the nation to reduce emissions of carbon dioxide, considered a leading cause of global warming. Representatives from nine Northeast states concluded two days of meetings Thursday, and, despite reports that a final agreement may be ready, decided that discussions would continue.

“I think it’s accurate to describe it as an exceptionally complex process,” said W. Michael Sullivan, director of the Rhode Island Department of Environmental Management who was at the meetings. “At this point, we’re still in the discussion explanation and fact-finding framework.”

Sullivan would not say whether there were disagreements among states at the discussions. He said officials in the meetings – which included the head of each state’s environmental agency – remain upbeat an agreement can be reached. A conference call has been scheduled for next month to discuss progress and perhaps schedule the next meeting, Sullivan said.

The states involved include the six New England states along with Delaware, New York and New Jersey.

Environmental groups were following the proceedings, even though they were closed to the public. Matt Auten, advocate for the Rhode Island Public Interest Research Group, said his and other environmental organizations remain optimistic a reduction plan will be achieved.

“It’s positive that the states are meeting,” he said.

Such an agreement would be the first of its kind in the nation and comes after the Bush administration decided not to regulate the greenhouse gases that contribute to global warming and rejected joining more than 150 other nations on the Kyoto anti-emissions treaty.