CHICAGO - BP sought to spread the blame for the Gulf of Mexico oil disaster on Wednesday, setting off a battle between oil industry giants with tens of billions of dollars in potential fines and legal liabilities at stake.

The British energy giant released a report concluding that a "sequence of failures" was to blame for the April 20 explosion that killed 11 people and unleashed 4.9 million barrels of oil in the worst-ever maritime spill.

While admitting some mistakes, BP exonerated its well design, and apportioned a large share of the blame to faults made by rig owner Transocean and oil services contractor Halliburton, which cemented the well.