NEW YORK (CNN/Money) - Merrill Lynch & Co. said Wednesday it fired two executives who declined to testify to federal investigators probing the Enron matter.

Merrill said it terminated Thomas W. Davis, vice chairman, and Schuyler Tilney, a managing director in investment banking.

They "have declined to testify in an investigation by the Securities and Exchange Commission and the U.S. Department of Justice into financial transactions initiated by Enron Corp. in 1999," Merrill said late Wednesday.

In July, Tilney exercised his Fifth Amendment right against self incrimination before the Senate Permanent Subcommittee on Investigations, which is looking into the role of prominent Wall Street banks in the collapse of Enron. Merrill placed Tilney on leave shortly after.

Merrill spokesman Mark Herr declined to offer any details about Davis' alleged lack of cooperation. Neither of the fired executives could be reached immediately for comment.

Merrill said it was enforcing its policy requiring employees to cooperate fully with regulatory and law enforcement investigations. Merrill also said it is not aware of any evidence that the employees acted improperly in their dealings with Enron.

Merrill Lynch (MER: Research, Estimates) shares fell 31 cents to $35.51 Wednesday before the news was released.

Enron filed for bankruptcy in December. Since then, the financial services industry has come under fire for its alleged role in helping Enron hide debt and create complicated deals to disguise the company's problems.

Merrill has said its relations with Enron included a $7 million equity investment in a company established to operate energy generation barges, as well as serving as a private placement agent for one of Enron's controversial partnerships.