ALBANY, N.Y. (AP) — The head of the state Environmental Conservation department said he was fired Thursday by Gov. David Paterson's top aide after his memo criticizing the governor's plan to cut staff was leaked.

DEC Commissioner Pete Grannis said the aide, Larry Schwartz, called him Wednesday and demanded his resignation over the leak, which Grannis says wasn't his doing. Grannis refused to resign and said Schwartz called him Thursday evening and fired him.

"He said, 'That's it, you're done, you're out effective immediately,'" Grannis said, speaking by phone from a meeting of the New York Water Environment Association, a sewage treatment industry group that had just given him an award.

The Paterson administration confirmed the firing late Thursday. An administration official said Grannis was fired for insubordination. The official spoke on the condition of anonymity because of the sensitivity of the issue and because there has been no public announcement.

The leaked memo said the 209 staff cuts Paterson demanded on top of 260 lost to early retirement incentives would seriously impede the agency's effectiveness.

"Many of our programs are hanging by a thread," stated the memo, which was reported by the Albany Times Union on Tuesday. "The public would be shocked to learn how thin we are in many areas. DEC is in the weakest position that it has been since it was created 40 years ago."

The memo warned that fewer polluted sites would be cleaned, stocking of game fish could be halted, and fewer regulators would be available to oversee the expected natural gas drilling boom in the Marcellus Shale that extends into southern New York.

Environmental, farm, and business groups have called on Paterson to reconsider the DEC staff cuts. The Independent Oil and Gas Association, which represents energy companies planning to drill in the Marcellus region, also weighed in, saying it feared a crippled bureaucracy would further hamper an industry that has been waiting for more than two years for the DEC to complete an environmental review and start issuing drilling permits.

"The agency has lost about 20 percent of its scientists, engineers and enforcement officials over the last few years," said Rob Moore, director of Environmental Advocates. "I think Governor Paterson has been dismantling the agency for two years and he's finally cut off its head."

Grannis was hired 40 years ago as a lawyer for the agency when it was created following the first Earth Day. He represented Manhattan's Upper East Side for more than 30 years in the Assembly, where he championed environmental issues, fighting for passage of the State Environmental Quality Review Act, the bottle deposit law and measures related to acid rain, clean air and water, recycling and brownfield cleanup.