The consortium of Tamoza Trading and Daxin Petroleum submitted an offer of 32.25 million euros (S$67.93 million) for a 69.99-per-cent stake in Yugoslav River Shipping (JRB), the agency said in a statement.
Second in the bidding was Malta's Palmali Shipping, followed by Cyprus-based company East Point Holding and Transport Trade Services of Romania.
The Privatisation Agency is expected to begin negotiations with the Singaporean consortium after it confirms the tender.
The two sides then have 30 days to clinch a deal for the sale of JRB, which has a range of cargo and passenger vessels as well as storage space and harbours along the Danube river.