Workers climb over a boom after cleaning oil from the Deepwater Horizon spill on a beach, Monday in Grand Isle, La.

New Orleans ? A federal judge struck down the Obama administration’s six-month ban on deepwater oil drilling in the Gulf of Mexico as rash and heavy-handed Tuesday, saying the government simply assumed that because one rig exploded, the others pose an imminent danger, too.

The White House promised an immediate appeal. Later Tuesday, Interior Secretary Ken Salazar said in a statement that within the next few days he will issue a new order imposing a moratorium that will eliminate any doubt it is needed and appropriate.

The Interior Department had imposed the moratorium last month in the wake of the BP disaster, halting approval of any new permits for deepwater projects and suspending drilling on 33 exploratory wells.

White House spokesman Robert Gibbs said President Barack Obama believes that until investigations can determine why the spill happened, continued deepwater drilling exposes workers and the environment to “a danger that the president does not believe we can afford.”

Several companies that ferry people and supplies and provide other services to offshore rigs argued that the moratorium was arbitrarily imposed after the April 20 explosion that killed 11 workers and blew out a well 5,000 feet underwater. It has spewed anywhere from 67 million to 127 million gallons of oil.

U.S. District Judge Martin Feldman, who was appointed by President Ronald Reagan and has owned stock in a number of petroleum-related companies, sided with the plaintiffs.

“If some drilling equipment parts are flawed, is it rational to say all are?” he asked. “Are all airplanes a danger because one was? All oil tankers like Exxon Valdez? All trains? All mines? That sort of thinking seems heavy-handed, and rather overbearing.”

He also warned that the shutdown would have an “immeasurable effect” on the industry, the local economy and the U.S. energy supply.

Feldman’s ruling was welcomed by the oil and gas industry and decried by environmentalists.

Feldman’s financial disclosure report for 2008, the most recent available, shows holdings in at least eight petroleum companies or funds that invest in them, including Transocean Ltd., which owned the Deepwater Horizon drilling rig that blew up. The report shows that most of his holdings were valued at less than $15,000; it did not provide specific amounts.

It was not clear whether Feldman still has any of the energy industry stocks. Recent court filings indicate he may no longer have Transocean stock. The 2008 report showed that he did not own any individual shares in big companies such as BP, which leased the rig that exploded, or ExxonMobil.

Feldman did not immediately respond to a request for more information about his current holdings.

Josh Reichert, managing director of the Pew Environment Group, said the ruling should be rescinded if the judge still has investments in companies that could benefit. “If Judge Feldman has any investments in oil and gas operators in the Gulf, it represents a flagrant conflict of interest,” Reichert said.

Feldman’s ruling prohibits federal officials from enforcing the moratorium until a trial is held. At least two major oil companies, Shell and Marathon, said they would wait to see how the appeals play out before resuming drilling.

In his ruling, the judge called the spill “an unprecedented, sad, ugly and inhuman disaster,” but said Salazar’s rationale for the moratorium “does not seem to be fact-specific and refuses to take into measure the safety records of those others in the Gulf.” Feldman said he was “unable to divine or fathom a relationship between the findings and the immense scope of the moratorium.”

The judge said the blanket moratorium “seems to assume that because one rig failed and although no one yet fully knows why, all companies and rigs drilling new wells over 500 feet also universally present an imminent danger.”

The lawsuit was filed by Hornbeck Offshore Services of Covington, La. CEO Todd Hornbeck said after the ruling that he is looking forward to getting back to work. “It’s the right thing for not only the industry but the country,” he said.

Earlier in the day, executives at a major oil conference in London warned that the moratorium would cripple world energy supplies. Steven Newman, president and CEO of Transocean, called it unnecessary and an overreaction.

“There are things the administration could implement today that would allow the industry to go back to work tomorrow without an arbitrary six-month time limit,” Newman said.