The US$91 million sub-contract is for the construction of the project's civil works, zone-1 and zone-2.

Speaking at the signing ceremony, Deputy Prime Minister Hoang Trung Hai required the project's main contractor, JGCS, and domestic sub-contractors, including Construction Corporation No1, to closely coordinate with the project's investor, consultant and supervisor to assure the project progresses on schedule and at a high quality, while maintaining a safe environment for workers and environmental protection standards.

The success of the project will help continuously build ties between domestic and foreign contractors in future projects, Hai added.

Hai also highly praised the JGCS's preparation for the project's construction and congratulated Construction Corporation No1 as the Vietnamese firm that could prove its competence and experience to be selected as a sub-contractor for the project.

Hai said that the Nghi Son project played an important role in the development of Thanh Hoa Province.

The project in the Nghi Son Economic Zone is one of Viet Nam's key projects on national energy security and socio-economic development strategies, and is the largest-ever in Southeast Asia and also the largest FDI project in Viet Nam – with capital topping $9 billion.

The project is a joint venture between PetroVietnam, with a 25.1 per cent stake, Kuwait Petroleum International with 35.1 per cent, Japan's Idemitsu Kosan with 35.1 per cent and Mitsui Chemicals with a 4.7 per cent investment.

Once commissioned in 2017 as scheduled, the project is expected to refine 200,000 barrels of crude oil per day, which is the equivalent of 10 million tonnes of oil per year. It is estimated it will create thousands of jobs during the construction period and more than 1,000 jobs when operational.