It will increase its annual capacity from the current 6.5 million tons of crude to 7.6 million tons.
In a document seeking approval from shareholders at its annual general meeting, company said the upgrade would finish within 6.5 years from the time it invites bids for the front-end engineering design.
It plans to borrow 70 percent of the cost.
Dung Quat in Quang Ngai Province and the Nghi Son Refinery in the central province of Thanh Hoa account for around 70 percent of the country’s fuel demand. The rest is imported.
In the first quarter of this year, Dung Quat had to operate at 105 percent capacity as Nghi Son cut production due to a cash crunch leading to gasoline shortages in the country.
Vietnam also plans to build a third refinery in the southern province of Ba Ria-Vung Tau with an annual capacity of 10 million tons.
It would take domestic production to 23 million tons, enough to meet demand.