The contract was signed on December 4 with EU's Innovation and Networks Executive Agency (INEA), with the financing being approved under the Connecting Europe Facility, the ministry said in a statement on Friday.
The total cost of the project design study is estimated at 12 million euro, including VAT.
The project will include the renovation of Ljubljana's main railway station, as well as the Siska, Zalog and Moste stations, and the railway infrastructure linking them. Works are expected to be completed by July 2023.
According to earlier media reports, the value of the entire upgrade project is seen at some 550 million euro.
($=0.824932 euro)