The judge who will allocate responsibility for the 2010 Gulf of Mexico oil spill has told lawyers to give him their views about whether a series of negligent acts can add up to gross negligence.

The Justice Department and private plaintiffs’ attorneys contend that BP PLC acted with gross negligence before the blowout on April 20, 2010. If U.S. District Judge Carl Barbier agrees, BP’s civil penalties could soar.

The blowout triggered an explosion that killed 11 workers on the Deepwater Horizon oil rig and spilled millions of gallons of oil into the Gulf. Barbier ultimately could decide how much more money BP, cement contractor Halliburton and rig owner Transocean Ltd. owe for their roles in the catastrophe.

The judge, who heard eight weeks of testimony, set June 21 as the deadline for post-trial briefs, listing six questions about gross negligence that he wants answered. Lawyers must also submit proposed findings and conclusions then.

BP has pleaded guilty to manslaughter and other criminal charges and agreed to pay $4 billion in criminal penalties. The company says it has racked up a total of more than $24 billion in spill-related expenses, including cleanup costs and compensation for businesses and individuals.

But the company still faces billions more in civil claims by the federal government and Gulf Coast states under the Clean Water Act, the Oil Pollution Act of 1990 and other environmental regulations.

Halliburton lawyers said Monday they are seeking a settlement.

Barbier asked the standard for finding gross negligence or willful misconduct under each law, and whether gross negligence must be traced to at least one act or can be based on “an accumulation or a series of negligent acts or omissions.”

He also asked whether rig employees could commit gross negligence, or whether such a finding would need to be traced “to shore-based or management-level employees.”

Would compliance with regulations shield a defendant from gross negligence, even if it knew “its conduct or equipment was unsafe, or violated accepted engineering standards?” he asked. And, he asked, “Does the fact that a party acted in accordance with `industry standards’ preclude a finding of gross negligence?”

The response deadline is July 12.

Barbier set page limits for the parties involved, including the states of Alabama and Louisiana and the team of private lawyers for Gulf Coast businesses and residents who claim they lost money because of the spill. The states can submit separate briefs and responses but must join the Plaintiffs’ Steering Committee on the proposed findings and conclusions, he wrote.

The first phase of trial was intended to identify the causes of the blowout of BP’s Macondo well and assign fault to the companies. The second phase, designed to determine how much crude spilled into the Gulf and what BP did to stop it, is scheduled to start in September.