HANOI--Russia's OAO Gazprom Neft is accelerating talks with Vietnam Oil and Gas Group, or PetroVietnam, to buy a stake in the Dung Quat oil refinery, PetroVietnam said Tuesday.

The two companies are aiming to sign a contract on the stake sale by the end of November, PetroVietnam said in a statement.

The 130,000-barrel-a-day Dung Quat refinery in central Vietnam was put into operation in 2009 and is the only operational refinery in the country. It meets a third of Vietnam's demand for transport fuels.

PetroVietnam has said it would sell a 49% stake in the refinery and would use the funds raised for an upgrade, so it can process more types of crude oil and raise its capacity to 200,000 barrels per day.

PetroVietnam said the two companies have agreed upon key negotiating points, including the refinery's expansion plan and the supply of Russian crude oil for the refinery.

Write to Vu Trong Khanh at trong-khanh.vu@wsj.com

Access Investor Kit for Gazprom OAO

Visit http://www.companyspotlight.com/partner?cp_code=A591&isin=RU0007661625

Access Investor Kit for Gazprom Neft OAO

Visit http://www.companyspotlight.com/partner?cp_code=A591&isin=RU0009062467

Access Investor Kit for Gazprom OAO

Visit http://www.companyspotlight.com/partner?cp_code=A591&isin=US3682872078

Access Investor Kit for Gazprom Neft OAO

Visit http://www.companyspotlight.com/partner?cp_code=A591&isin=US36829G1076