The state is prepared to sell up to 70% of the company, reducing its holding to 30%, according to deputy transport minister Nguyen Hong Truong.
New investors can be either Vietnamese or foreign, he added.
The government hopes to complete the company's restructuring this year, following sell-offs after it ran up huge debts in the financial crisis.
The Dau Tu newspaper earlier reported that it planned to conduct an IPO in the first quarter of 2015.
TradeWinds
