By Nate Raymond
(Reuters) - Two former BP Plc supervisors won the dismissal on Tuesday of some of the manslaughter charges facing them over the Gulf of Mexico drilling rig explosion that killed 11 people in 2010.
U.S. District Judge Stanwood Duval in New Orleans dismissed 11 counts of seaman's manslaughter facing Deepwater Horizon rig well site leaders Robert Kaluza and Donald Vidrine.
But the judge refused to dismiss 11 other counts of involuntary manslaughter, leaving those and a Clean Water Act violation charge to be heard at a trial starting in June.
David Gerger, a lawyer for Kaluza, said he was reviewing the decision.
A lawyer for Vidrine and representatives for the U.S. Justice Department did not immediately respond to requests for comment.
Kaluza and Vidrine were the two highest-ranking supervisors on board the Deepwater Horizon when disaster struck on April 20, 2010, sending millions of barrels of oil into the Gulf of Mexico.
The indictment accused the men of "negligent and grossly negligent" supervision of testing at the well in the run up to the explosion.
The charges were announced on November 15 last year, the same day BP agreed to pay $4 billion and plead guilty 14 criminal counts over conduct leading up to and after the disaster.
A trial is currently underway in the case of another employee, former BP engineer Kurt Mix, who is accused of deleting records related to the estimated size of the spill. He denies wrongdoing.
In his ruling on Tuesday, Duval rejected the arguments by lawyers for Kaluza and Vidrine that the Outer Continental Shelf Lands Act did not extend federal law to the outer continental shelf, where Deepwater Horizon was located.
But the judge accepted the defendants' arguments that the seaman's manslaughter charges did not extend to them as oil well site leaders with no navigation function on the Deepwater Horizon.
Duval said his ruling was the first in the statute's 175-year history to apply the law to a drilling rig blow-out, and he acknowledged the "risk of explosion on board deepwater drilling facilities is a grave matter.
But Duval said he "refuses to expand the scope of the statute unnecessarily without certainty as to Congress' intent to do so."
The case is U.S. v. Kaluza, U.S. District Court, Eastern District of Louisiana, No. 12-cr-00265.
(Reporting by Nate Raymond in New York; Editing by Tim Dobbyn)