A judge blocked the six-month moratorium on new deepwater drilling imposed by the Obama administration after the Gulf of Mexico oil spill, a ruling the White House immediately said it would appeal.
Several companies that ferry people and supplies and provide other services to offshore drilling rigs had asked U.S. District Judge Martin Feldman in New Orleans to overturn the moratorium.
President Barack Obama's administration has halted the approval of any new permits for deepwater drilling and suspended drilling at 33 exploratory wells in the Gulf.
Judge Feldman said in his ruling that the Interior Department failed to provide adequate reasoning for the moratorium. He said it seemed to assume that because one rig failed, all companies and rigs doing deepwater drilling posed an imminent danger.