Alabama is suing BP Plc, Transocean and Halliburton for "catastrophic harm" caused by the Gulf of Mexico oil spill, the state's attorney general said on Friday.
Alabama is the first state to sue BP for damage from the world's worst offshore oil spill.
The decision stems from fear economic victims will be inadequately compensated and BP will shirk its financial responsibility, Attorney General Troy King said.
"We are making this claim because we believe that BP has inflicted catastrophic harm on the state ... We are suing them for the amount it will take to make Alabama whole," King told Reuters, declining to specify a figure for damages.
BP had no immediate comment, a company spokeswoman said.
The suit also named Anadarko Petroleum Corp
Transocean owned the doomed Deepwater Horizon drilling rig that was hired by BP and exploded and sank in April, triggering the oil spill. Halliburton provided the cement work for the well while Anadarko was a minority owner.
"It is believed the explosion on the Deepwater Horizon was a blowout relating to the cementing work," the suit said.
Alabama's state government is divided over the lawsuit. Governor Bob Riley said in a statement he opposed the decision on the grounds that it was premature to sue BP before it has a chance to pay claims, especially given that the company has admitted it is responsible.
King argued the suit put Alabama in the strongest legal position and said that, while an out of court settlement was possible, the next step was discovery and gathering evidence.
The suit accuses BP and the other defendants of "negligent or wanton failure to adhere to recognized industry standards of care."
"The defendants' conduct in operating the Deepwater Horizon and oil well illustrates their scheme to maximize profits and ignore dangerous risks posed to human health and property," it said.
Louisiana sustained the most damage to its coastline and waters from the oil spill, which began in April and was plugged with cement on July 15.
Oil also damaged the economies of Mississippi and Florida.
The spill has hurt industries including fishing and tourism and has affected other sectors such as housing. People and businesses that have sustained losses can claim against a $20 billion BP compensation fund administered by Kenneth Feinberg, named by the White House as an independent overseer.
But Feinberg was undermining efforts by Gulf state attorneys general to make it possible for spill victims to claim damages from the fund while retaining the right to sue BP at a future date, King said.
At the same time, he said, BP was seeking to evade its responsibility despite a high-profile advertising campaign which states "we will make this right" and promises to honor all legitimate claims.
Mississippi Governor Haley Barbour in July asked his state's attorney general not to file a suit against BP to give the federal claims process a chance to work and to allow for a complete assessment of damage to natural resources.