McKay, currently head of BP's oil and gas production, or upstream business, will be succeeded by Bernard Looney, currently chief operating officer of upstream production, BP said.

"These changes simplify, focus and better align accountabilities within our experienced and versatile senior team," Chief Executive Officer Bob Dudley said in a statement.

"In particular Lamar's new role will allow us to further concentrate our attention on BP's highest priorities through this challenging time for our whole industry."

(Reporting by Ron Bousso, editing by Louise Heavens)