(Reuters) — A federal appeals court on Monday cleared the U.S. Securities and Exchange Commission to resume civil proceedings against a former Standard & Poor's executive over an alleged fraud involving mortgage debt ratings.

In a brief order, the 2nd U.S. Circuit Court of Appeals vacated a preliminary injunction that had halted the SEC's in-house administrative proceeding against Barbara Duka.

The appeals court cited a June 1 decision in which it rejected as premature a constitutional challenge by New York financier Lynn Tilton to a similar proceeding.

It returned Ms. Duka's case to U.S. District Judge Richard Berman in Manhattan, who issued the injunction Aug. 12, 2015, for further proceedings consistent with the Tilton decision.

Guy Petrillo, a lawyer for Ms. Duka, did not immediately respond to requests for comment. The SEC was not immediately available for comment.

Ms. Duka, Ms. Tilton and other defendants have objected to the SEC's use of in-house courts, saying the appointment of the presiding judges and hurdles that can make it impossible for the president to remove those judges are unconstitutional.

Administrative proceedings also offer procedural advantages that can make it easier for the SEC to win.

The SEC accused Ms. Duka, a former head of S&P's commercial mortgage-backed securities group, of concealing how the agency had eased its criteria for calculating some ratings in 2011.

In halting that case, Judge Berman had said the appointment of SEC judges was likely unconstitutional.

But in the Tilton case, the 2nd Circuit ruled 2-1 that a defendant could not challenge an administrative proceeding's constitutionality before a final decision had been rendered.

The SEC began pursuing more cases in-house under powers granted by the 2010 Dodd-Frank financial reforms.

S&P, a unit of S&P Global Inc, agreed in January 2015 to pay $77 million to settle charges by the SEC and the attorneys general of New York and Massachusetts related to the Duka case.