(Adds quote from court)
HOUSTON, Sept 4 (Reuters) - A federal judge has found oilgiant BP Plc "grossly negligent" for its role in the 2010spill in the Gulf of Mexico, a ruling that could add billions ofdollars in fines to the more than $42 billion in charges takenso far for the worst offshore disaster in U.S. history.
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 theresult of gross negligence or willful misconduct' by BP, theruling from U.S. District Judge Carl Barbier said.
The company has shrunk since it was forced to sell assets topay for the disaster aboard the Deepwater Horizon drilling rigthat killed 11 workers.
Barbier has yet to assign damages from the spill under thefederal Clean Water Act, though previous calculations by Reutershave shown fines could run to $17.6 billion in the costliestscenario.
Barbier apportioned 67 percent of the fault to BP, 30percent to Transocean Ltd, which owned the drillship,and 3 percent to Halliburton, which did cement work onthe Macondo well that blew out. (Reporting by Sudip Kar-Gupta and Karolin Schaps; editing byKate Holton; Writing by Terry Wade)
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