The multibillion-dollar trial of BP over its part in the worst oil spill ever in the US, which had been due to begin on Monday, has been postponed.

BP is accused of ultimate responsibility for the 2010 Deepwater Horizon rig disaster, when an explosion in a well led to the deaths of 11 workers and hundreds of millions of gallons of oil leaking across the Gulf of Mexico.

The case, which could last two years, will begin on March 5, BP said on Sunday night.

BP and the Plaintiffs' Steering Committee confirmed that the US District Court in New Orleans had adjourned the start of the trial by a week to allow them to continue discussing a possible settlement agreement.

BP potentially faces fines and liabilities of up to $52bn (£32bn) from the case, according to some analysts. The corporation has set aside $40bn to deal with the fallout from the spill, and has paid out around $7bn in compensation to families of victims and others whose livelihoods were affected.

Transocean and Halliburton are also on trial. Bob Dudley, BP's chief executive, who replaced Tony Hayward after the disaster, told the Sunday Telegraph: "We have to remember we are a business that invests in decade-long cycles.

"If [the trial] goes to 2013 or 2014, in the history of BP and the way the energy industry works we just have to think much longer term. Hopefully we will reach some agreements and we will be able to reduce the uncertainty and move forward. But the appeals process has various different branches it could go down in terms of time so it could be a lot longer than that [2014]."

Whether BP settles or not, the case is virtually guaranteed to prove the most expensive environmental disaster in history, far surpassing the Exxon Valdez spill off the coast of Alaska, and any payoff would dwarf previous deals the US government has reached with corporate offenders in any industry (a record that currently stands at $2.3bn for Pfizer over painkillers).

The blowout on 20 April 2010 of the Macondo well killed 11 and injured 17 workers, setting fire to the Deepwater Horizon rig which toppled and sank. Engineers took 85 days to permanently cap the well, by which time leaking oil had spread, endangering fisheries, killing marine life, closing beaches and contaminating more than 900 miles of shoreline.

However, BP denies gross negligence, and says responsibility should be shared with their co-defendants: Transocean, the rig's owners, and Halliburton, the firm contracted to seal the well. Mike Brock, a BP trial lawyer, said BP was ready to prove "that no single action, person or party was the sole cause of the blowout".

The plaintiffs include the federal government, the governments of Louisiana and Alabama, and more than 110,000 people and businesses, including large fishing and hotel operations, with claims against the company. There are 340 lawyers from 90 different firms working for the plaintiffs.

A key first witness will be Robert Bea, a Berkeley professor specialising in investigating industrial accidents, who was consulted by the White House commission investigating the explosion and has produced four reports faulting BP and its partners for their attitude towards safety, stating that the disaster was preventable.

Dudley said that BP had changed procedures since the accident and now adhered to "the toughest standards". He said that the new, smaller BP had "turned the corner" after making $23.9bn annual profits in 2011.

The Sunday Times has reported that BP's one-time boss Lord Browne may end up controlling some of the North Sea oil fields that Dudley is planning to sell off in the wake of the Deepwater disaster. The paper claims Browne plans to create a new company via Riverstone, the American investment company, with a view to buying BP's North Sea assets.