The Federal Trade Commission's ethics officer has given President Bush's nominee to head the agency the go-ahead to participate in oil and gas industry cases, though she represented a major oil company within the past year.

The ethics officer's decision, released late yesterday, sought to address concerns from two Democratic senators who are opposing Deborah P. Majoras's nomination to replace current chairman Timothy J. Muris, who is leaving this summer.

"Because the chairman's participation in FTC petroleum matters is particularly important, Ms. Majoras's brief representation of ChevronTexaco would not be disqualifying," wrote Christian S. White, the agency's designated ethics official, in a letter to the Senate Commerce Committee. White said that government rules permit an ethics official to authorize an employee who may have a potential conflict-of-interest to participate in matters where "the interest of the government . . . outweighs the concern" of any partiality.

White's letter didn't assuage the criticisms of Sens. Ron Wyden (D-Ore.) and Barbara Boxer (D-Calif.) who have said they will try to block the Senate from voting on her nomination until she offers a concrete plan to make the FTC more active in overseeing competition in the oil industry.

"It would not be enough for the FTC ethics officer to waive the rules and let Ms. Majoras participate. That would not eliminate the conflict, nor would it increase the likelihood that Americans paying astronomical gas prices will finally get the true advocate they need in this post," Wyden said in a statement.

The ethics officer also said that Majoras has agreed not to participate in cases in which her husband's law firm, Jones Day, represents a client. Majoras has also been at Jones Day since January, when she left the Justice Department, where she was an antitrust official.

White said that that recusal would be limited, noting that while Majoras was at Justice, she recused herself from about 30 matters because of Jones Day's involvement.