NEW ORLEANS (AP) -- Plaintiffs' attorneys have rested their case at a trial over the deadly Deepwater Horizon rig explosion and massive 2010 oil spill in the Gulf of Mexico.

A federal judge heard testimony by more than a dozen witnesses called by the Justice Department and private attorneys for Gulf Coast residents and businesses. The plaintiffs' lawyers rested Wednesday after their last witness, a former employee of cement contractor Halliburton (HAL 0.13%), finished testifying.

The trial continues with more testimony by witnesses for rig owner Transocean (RIG 1.31%), whose chief executive testified Tuesday. BP (BP -0.40%) and Halliburton also will call their own witnesses.

U.S. District Judge Carl Barbier is hearing testimony without a jury. Barring a settlement, he could decide how much more money the companies owe for their roles in the nation's worst offshore oil spill.