By Lawrence Hurley

WASHINGTON (Reuters) - A U.S. appeals court on Thursday said it would rehear a challenge to the Securities and Exchange Commission's use of in-house judges.

The order issued by the U.S. Court of Appeals for the District of Columbia Circuit wiped out a three-judge panel's August decision in favor of the commission.

The court indicated that 10 of the court's judges will hear the case. Oral arguments will be held on May 24.

Former radio host Raymond Lucia brought the challenge, arguing that the agency's administrative law judges were unconstitutionally appointed. Lucia, known for his "Buckets of Money" investment strategy, was hoping to beat back fraud charges.

The SEC has in recent years has come under attack by defendants who have questioned the fairness of its in-house trials.

In December, a federal appeals court in Denver ruled that the appointments process was unconstitutional, raising the prospect of the question ultimately being decided by the Supreme Court.

Administrative law judges are independent from the government agencies where they work. Their employing agency can seek their removal, but such a move must also be reviewed by the Merit Systems Protection Board.

Defense attorneys, including attorneys for Lucia, have argued that the appointment of SEC administrative law judges, and the hurdles that can make it impossible for the president to remove those judges, are unconstitutional and violate the separation of powers clause.

The case raises similar issues to a separate challenge to the appointment of the U.S. Consumer Financial Protection Bureau's director, which the court also said on Thursday it would rehear.

(Reporting by Lawrence Hurley; additional reporting by Sarah N. Lynch; Editing by Jonathan Oatis)