WASHINGTON - The Justice Department on Wednesday sued BP P.L.C. and eight other companies over the Gulf of Mexico oil spill in an effort to recover billions of dollars from the largest offshore spill in U.S. history.

The government's lawsuit asks that the companies be held liable without limitation under the Oil Pollution Act for all removal costs and damages caused by the oil spill, including damages to natural resources. The lawsuit also seeks civil penalties under the Clean Water Act.

"We intend to prove these violations caused or contributed to the massive oil spill," Attorney General Eric H. Holder Jr. said at a news conference.

The lawsuit is the first brought by the United States over the oil spill. The amount of damages and the extent of injuries sustained by the United States as a result of the Deepwater Horizon spill are not yet fully known, the lawsuit states.

The suit, said BP spokesman Scott Dean, "is solely a statement of the government's allegations and does not in any manner constitute any finding of liability or any judicial finding that the allegations have merit."

"Alone among the parties, BP has stepped up to pay for the cleanup of the oil, setting aside $20 billion to pay all legitimate claims," Dean said in an e-mail.

The federal lawsuit says inadequate cementing of the well contributed to the disaster. Similar allegations were made by BP in its internal investigation, and by the independent presidential oil-spill commission. But Halliburton Co., the contractor in charge of mixing and pumping the cement, is not named in the government suit.

An explosion that killed 11 workers at BP's Macondo well on April 20 led to oil spewing from the company's undersea well - more than 200 million gallons in all by the government's estimate. BP disputes the figure.

The suit was filed in federal court in New Orleans.

The lawsuit alleges that safety and operating regulations were violated in the period leading up to April 20.

It says that the defendants failed to keep the Macondo well under control during that period and failed to use the best available and safest drilling technology to monitor the well's condition. They also failed to maintain continuous surveillance and failed to maintain equipment and material that were available and necessary to ensure the safety and protection of personnel, equipment, natural resources, and the environment, the suit alleges.

Other defendants include units of Transocean Ltd., which owned the drilling rig; Anadarko Petroleum Corp.; and MOEX Offshore 2007 L.L.C., part owners of the well that ruptured.

"No drilling contractor has ever been held liable for discharges from a well under the Oil Pollution Act of 1990," Guy Cantwell, a Transocean spokesman, said in an e-mail. "The responsibility for hydrocarbons discharged from a well lies solely with its owner and operator."

MOEX Offshore said it was reviewing the complaint. Anadarko said it was not involved in the operation of the oil rig or in decisions involving it.