LONDON - Riyadh Air will announce a deal to buy a "sizeable" number of narrowbody aircraft in the coming weeks, the start-up airline's chief executive said, as he helps shape a second carrier for Saudi Arabia.

Former Etihad Airways boss Tony Douglas was hired in March to head up Riyadh Air, owned by Saudi Arabia's Public Investment Fund. With 72 Boeing 787 widebody jets already provisionally ordered, Douglas said narrowbodies were next.

"We have concluded our narrowbody campaign," he said in an interview in London on Monday. "I think we will probably be announcing it within the coming weeks."

(Reporting by Sarah Young, Editing by Pauil Sandle)