The Obama administration said on Friday it is essential that its ban on deepwater oil drilling be restored after a court struck it down and promised a revised moratorium would be announced soon.

Interior Secretary Ken Salazar told reporters in California he will make an announcement on a new ban on deepwater drilling in the "next several days."

His comments came a day after a federal court refused to reinstate the six-month ban on deepwater drilling below 500 feet, which the Obama administration imposed after BP Plc's massive oil spill in the Gulf of Mexico.

The U.S. Court of Appeals for the Fifth Circuit ruled 2-1 against the administration's request to stay a lower court decision lifting the ban, saying the government failed to show how it would be irreparably harmed if it were not granted.

The administration said it did not consider the ban a major setback for the policy because it lets the Interior Department apply to stop a project if an operator attempts to start deepwater drilling in the Gulf.

The flow of oil from BP's blown-out Macondo well is killing birds, sea turtles and dolphins, imperiling multibillion-dollar fishing and tourist industries at a time of high unemployment, and soiling the shores of all five U.S. Gulf Coast states.

The court ruling pushed shares of Transocean Ltd, the world's largest offshore drilling contractor, up more than 5 percent on the Zurich exchange on Friday. They had lost almost half their value since April.

Transocean owns the BP-leased rig that exploded in the Gulf of Mexico in April, triggering the biggest oil spill in U.S. history.

The administration said it imposed the moratorium to allow enough time for an investigation of the disaster. The energy industry fears the ban could put costly projects on hold.

Diamond Offshore Drilling Inc said on Friday it was pulling one of its deepwater rigs out of the Gulf, the first such move resulting from uncertainties surrounding the U.S. moratorium.