* CDU expected to be in production within 10 days
* Overhaul of other units continues at Whiting refinery (Adds Genscape report on Whiting CDU)
HOUSTON, June 21 (Reuters) - BP Plc on Friday wasstarting up the revamped crude distillation unit at the heart ofa $4-billion overhaul of its 405,000-barrel-per-day (bpd)Whiting, Indiana, refinery, said sources familiar with refineryoperations.
The start-up is expected to finish within 10 days, and the260,000 bpd CDU will be moving to full production over three tofour weeks, the sources said.
Energy industry intelligence service Genscape said on Fridaythat the start-up was underway based on increased furnace stackactivity coming from the unit, called Pipestill 12.
BP shut Pipestill 12 in November as part of a plannedoverhaul of the refinery to increase its capacity to refinecheaper Canadian crude oil from 80,000 bpd to 350,000 bpd.
A BP spokesman declined to discuss the status of Pipestill12, but reiterated that the company expects the unit will returnto production by the end of June.
Work on other units at the refinery will continue into thesecond half of the year, when the refinery-wide project isscheduled for completion.
Construction on the project is more than 90 percent completea BP official told the Lakeshore Chamber of Commerce in Hammond,Indiana, on Thursday, according to a report in the NorthwestIndiana Times.
A crude distillation unit does the initial refining of crudeoil coming into the refinery and provides feedstock for allother units.
Pipestill 12 is the largest of three CDUs at the Whitingrefinery. The other two CDUs have continued operating whilePipestill 12 has been shut.
BP has shifted its U.S. refining strategy to focus onplants in the northern United States that can run cheaper crudeoil from Canada's tar sands fields in Alberta. (Reporting by Erwin Seba; Editing by Bernard Orr and TimDobbyn)