Updated

The first BP executive to testify at a federal trial over the nation's worst oil spill will take the stand again Wednesday before a judge tasked with deciding whether the oil giant and other companies acted with gross negligence for the 2010 disaster in the Gulf of Mexico.

BP executive Lamar McKay testified Tuesday, the second day of the non-jury trial in New Orleans. He said BP and its contractors share responsibility for preventing blowouts like the one that triggered a rig explosion that killed 11 workers on April 20, 2010, spawning the vast spill.

Rig owner Transocean Ltd. and cement contractor Halliburton also are defendants at the trial, which opened Monday before U.S. District Judge Carl Barbier.