WASHINGTON  A federal appeals court on Thursday turned down the Obama administration’s effort to enforce a six-month moratorium on deepwater drilling in the Gulf of Mexico.

A three-judge panel of the United States Court of Appeals for the Fifth Circuit, in New Orleans, ruled shortly after a hearing in a lawsuit filed by companies that claim they are being financially crippled by the suspension of drilling.

The Interior Department said the moratorium was necessary because of the uncertainties about the cause of the BP oil well blowout in April, a shortage of response equipment and a need to write strict new drilling rules. The moratorium was struck down by a lower court on June 22 by a federal judge who found it arbitrary and economically ruinous to industry.

The appeals court found that the Interior Department failed to show the federal government would suffer “irreparable injury” if the moratorium is lifted while it appeals the trial court’s decision.