An investment advisory firm filed a lawsuit yesterday in federal court in Manhattan against the New York attorney general, Eliot Spitzer, saying he overstepped his authority with a subpoena for information concerning fees paid to the firm.

In its lawsuit filed in the Southern District of New York, J. & W. Seligman & Company, a New York investment adviser, asks that Mr. Spitzer’s office be enjoined from seeking information on advisory fees, saying that area of regulation has been delegated to the Securities and Exchange Commission.

“Plaintiffs are respectful of defendant and the work he has done in the public interest, but believe that, in this instance, he has exceeded his authority and intruded himself into an area assigned by Congress to the SEC,” the lawsuit says.

A spokesman for Mr. Spitzer did not immediately have a comment yesterday.

The complaint says Mr. Spitzer’s office and the SEC began an investigation of Seligman in February 2004 after the company’s voluntary disclosure of a short-lived arrangement in 2002 with a Chicago-based brokerage firm to permit a limited amount of frequent trading in certain mutual funds managed by Seligman.

The company began negotiations with the SEC and Mr. Spitzer’s office to settle the matter in March and reached a tentative agreement on the financial terms of the settlement in mid-August, the lawsuit says.

However, Seligman said in its lawsuit that it found certain operating conditions sought by Mr. Spitzer’s office as part of the pact as “unacceptable” – namely, effectively turning over control of the negotiation of advisory fees to an outsider and subjecting the negotiation process to the oversight and control of Mr. Spitzer’s office in perpetuity.

The lawsuit says the company advised Mr. Spitzer’s office during the week of August 22 that it would reluctantly meet the monetary demands of the settlement, but that “it could not live with the other conditions defendant sought to impose.”

On August 26, Mr. Spitzer’s office issued a “bevy of subpoenas” to the independent directors of Seligman Funds, the funds themselves, Seligman’s principal shareholder, and its president seeking information on allegedly “excessive” advisory fees paid to the firm, the complaint says.

“These subpoenas were, it would seem, a pressure tactic by defendant to compel Seligman to yield to defendant’s unacceptable conditions of settlement,” the lawsuit claims.

The lawsuit claims allowing Mr. Spitzer to seek such information or continue an investigation into advisory fees would “open the door to 50 different state attorneys general doing the same thing, thus defeating the carefully conceived and comprehensive federal regulatory scheme enacted by Congress.”