NEW ORLEANS (AP) - BP is scheduled to call its first witness at a trial designed to determine causes and assign blame for its April 2010 well blowout in the Gulf of Mexico.

The BP witnesses are scheduled to start appearing Monday.

They follow testimony presented by Halliburton, BP PLC's cement contractor on the Deepwater Horizon drilling project.

Halliburton rested its case Thursday at the end of the trial's sixth week.

BP witness testimony is expected to last at least two weeks.

US District Judge Carl Barbier is hearing testimony. Barring a settlement, he could decide how much more money BP and its contractors owe for their roles in the catastrophe.

The trial's first phase should conclude this month. Judge Barbier plans to hold a second phase that examines BP's efforts to stop the spill.