Halliburton Largely Off The Hook For Deepwater Horizon Spill Responsibility
Well-known oil services company Halliburton, however, avoided BP's level of responsibility for the spill.
Shares of BP traded in the United States fell 5 percent, or $2.40, to $45.31.
"The Court concludes that the discharge of oil 'was the result of gross negligence or willful misconduct' by BP, the ruling from U.S. District Judge Carl Barbier said.
Barbier apportioned 67 percent of the fault to BP, 30 percent to Transocean Ltd, which owned the drillship, and 3 percent to Halliburton, which did cement work on the Macondo well that blew out.
The company has shrunk since it was forced to sell assets to pay for the disaster aboard the Deepwater Horizon drilling rig that killed 11 workers.
Barbier has yet to assign damages from the spill under the federal Clean Water Act, though previous calculations by Reuters have shown fines could run to $17.6 billion in the costliest scenario.
(Reporting by Sudip Kar-Gupta and Karolin Schaps; editing by Kate Holton; Writing by Terry Wade)