KHOBAR, (Reuters) – Foreign engineering firms have submitted bids to design Saudi Aramco’s Jizan crude oil refinery, industry sources said on Tuesday.

Companies had asked the state oil firm for more time but the due date for the front-end engineering and design (FEED) and project management services (PMS) closed on Dec. 25 as set by Aramco, sources said.

The refinery is designed to process 400,000 barrels per day (bpd) of crude and is part of Saudi Arabia’s plans to boost domestic refining capacity from the current level of 2.1 million bpd.

Seven international engineering firms submitted their proposals, of which 5 were U.S. companies: KBR, Foster Wheeler, Mustang Engineering, Fluor and Jacobs Engineering.

France’s Technip and Australia’s WorleyParsons have also participated in the bidding process.

Saudi Arabia had hoped the refinery would be built and owned entirely by the private sector, a first in the world’s top oil exporter.

Last year, the government handed over the delayed project to Aramco. The refinery is to be built in Jizan, far from the kingdom’s producing oilfields, as part of a wider development plan to revive the impoverished southern region.

The plant is to produce around 75,000 bpd of gasoline, 100,000-160,000 bpd of ultra-low-sulphur diesel and 160,000-220,000 bpd of fuel oil depending on the crude mix processed.

It would be integrated with a power and water facility. A marine terminal would also be built and is expected to be completed by 2016.