Tens of billions of dollars are at stake in the complex trial -- previously due to start Monday -- in which a federal judge will rule on whether deadly missteps constitute gross negligence and assign a price tag to the damages.
Judge Carl Barbier adjourned the trial until March 5 "for reasons of judicial efficiency and to allow the parties to make further progress in their settlement discussions."
BP said in a statement that the delay was aimed at allowing it "more time to continue settlement discussions and attempt to reach an agreement" with the Plaintiffs' Steering Committee.
That committee is charged with handling the claims of thousands of people and businesses affected by the spill, which blackened beaches in five US states and devastated the Gulf Coast's tourism and fishing industries.
A settlement with that committee would not mark the end of the case, nor would it resolve the bulk of BP's liabilities.
BP still faces staggering fines and potentially criminal charges from the federal government and must also resolve claims brought by state and local governments.
It also still hopes to shift some of the financial burden onto Transocean, which operated the Deepwater Horizon offshore drilling rig, and Halliburton, which was responsible for the faulty cement job on the runaway well.
Asked about the status of settlement negotiations with the government and its subcontractors, a BP spokesman declined to comment.
"BP and the PSC are working to reach agreement to fairly compensate people and businesses affected by the Deepwater Horizon accident and oil spill," BP said in a joint statement with the Plaintiffs' Steering Committee.
"There can be no assurance that these discussions will lead to a settlement agreement. A further announcement will be made as appropriate."
The April 20, 2010 explosion aboard the BP-leased Deepwater Horizon killed 11 workers and spewed 4.9 million barrels (206 million gallons) of oil into the Gulf of Mexico.
It took 87 days to cap the runaway well some 5,000 feet (1,500 meters) below the surface and 50 miles (80 kilometers) off the coast of Louisiana.
Several government probes spread the blame among BP, Transocean and Halliburton and castigated them for cutting corners and missing warning signs that could have prevented the disaster.
Barbier -- an expert in maritime law with a reputation for efficiency who consolidated hundreds of spill-related lawsuits into a single federal case -- is tasked with determining how much of the blame rests with each party and whether punitive damages should be imposed.
BP -- which reported a $23.9 billion profit for 2011 -- has said it is working to reach a settlement with the US government over a host of civil fines and possible criminal charges.
"We are prepared to settle if we can do so on fair and reasonable terms, but equally, if this is not possible, we are preparing vigorously for trial," chief executive Bob Dudley said after BP surged back into the black on February 7.
That settlement will likely come in at a record $20 to $25 billion, Morgan Stanley estimated in a recent research note.
That would significantly exceed the $12 billion provision that BP set aside for those penalties as part of the $41 billion charge it posted in 2010 to cover spill-related costs, analyst Martijn Rats wrote.
BP has already paid more than $6 billion to over 220,000 claimants who chose to settle with a special fund set up to provide emergency payments and a faster route to reimbursement.
The massive cleanup and containment effort cost BP $13.6 billion.
It has been able to recover some of the costs from its well partners and subcontractors but warned in its quarterly report that the final tally for the spill is "subject to significant uncertainty."