LONDON (Reuters) - BP as a part of a reshuffle has named Ariel Flores as head of its North Sea operations to oversee expansion there, a spokesman said.

Flores will become Regional President, North Sea Region, with effect from March 15. He has been with BP for 19 years, most recently as manager of BP's operations in Iraq's giant Rumaila oilfield.

The ageing North Sea basin is one of BP's core regions. It plans to double production to 200,000 barrels per day by 2020 following the start-up of the Quad 204 field in the western Shetlands last year. It has recently made two discoveries there.

Flores will replace Mark Thomas after more than two years in the job. Thomas will become joint head of the BP chief executive's office alongside Norman Christie, currently regional president for BP Trinidad.

Thomas and Christie replace Carol Howle, who became CEO, BP Shipping, at the beginning of February. In April, William Lin, will take up the role of Chief Operating Officer, Upstream Regions.

(Reporting by Ron Bousso; editing by Jason Neely)

By Ron Bousso