The ruling is not the final word on the Obama administration's fight to suspend new drilling projects so it can study the risks revealed by the disastrous BP oil spill.
The same appeals court is expected to hear arguments on the merits of the moratorium case in late August or early September.
While it's possible that 33 exploratory wells suspended by the moratorium could resume drilling, companies might not bother with the expense while the ultimate future of the projects hangs in the balance.
Catherine Wannamaker, a lawyer for several environmental groups that support the moratorium, said she was disappointed by the ruling but expressed confidence that the Obama administration ultimately will win its appeal.
Wannamaker said it's unclear whether any offshore companies would resume drilling because Thursday's ruling doesn't resolve the case.
"Clearly, it's legally allowed," he said. "The question is, practically speaking, will anybody do it given the uncertainty? It's hard to know what will happen."
The CEO of one of the companies that sued to stop the moratorium, Covington-based Hornbeck Offshore Services, said he didn't know if any of the companies involved planned to resume drilling.
"We need to get back to work," Todd Hornbeck said of his company, which provides vessels that serve the offshore industry. "We can't work without any drilling units working."
The moratorium, which prompted a lawsuit from oil and gas service companies, was first rejected June 22 by U.S. District Judge Martin Feldman.