ALBANY — Two wind farm developers with projects across upstate New York are under investigation by the state attorney general.

On Tuesday, Attorney General Andrew M. Cuomo announced that First Wind and Noble Environmental Power LLC are being investigated "amid allegations of improper dealings with public officials and anti-competitive practices."

"The use of wind power, like all renewable energy sources, should be encouraged to help clean our air and end our reliance on fossil fuels," Mr. Cuomo said in a press release. "However, public integrity remains a top priority of my office and if dirty tricks are used to facilitate even clean-energy projects, my office will put a stop to it."

Mr. Cuomo has issued subpoenas to both companies, seeking:

■ All documents concerning any benefits conferred on any individual or entity in connection with wind farm activity.

■ All agreements, easements or contracts with individuals regarding placement of wind turbines.

■ Agreements between wind companies that may indicate anticompetitive practices.

■ All documents pertaining to any payments or benefits received from local, state or federal agencies.

First Wind, which changed its name from UPC Wind in May, has three operational wind farms and several others in various stages of development in Hawaii, Oregon, Maine, Utah, Vermont, New York and New Brunswick, Canada.

The company's Steel Winds I wind farm in Lackawanna is already operational. Its other upstate New York projects include GenWy Wind in Genesee and Wyoming counties as well as one in Prattsburgh and Italy (Steuben and Yates counties), two in Cohocton (Steuben County) and one in Chautauqua County.

"We have received the subpoena," said John Lamontagne, spokesman for First Wind. "We intend to cooperate fully with the attorney general's office."

In addition to projects in Michigan, New Hampshire and Vermont, Noble Environmental is developing five wind farms in the north country and four more in Western New York. Its north country projects are farms at Bellmont and Chateaugay in Franklin County, and at Altona, Clinton and Ellenburg in Clinton County. In Western New York, Noble's wind farms are at Bliss (operational) and Wethersfield in Wyoming County, at Altona, Allegany County, and at Ball Hill, Chautauqua County.

The company also said it would cooperate with the subpoena.

"Noble has received a civil subpoena from the Attorney General of New York State regarding wind development activities in New York," said Walt Howard, Noble's chief executive officer, in a press release. The company is in the process of reviewing the subpoena and will cooperate fully with the Attorney General. We are confident the Attorney General's inquiry will find that Noble's actions have been legal and proper and we look forward to his review."