Merseytravel has hired rail contractor First Engineering for the project to reopen the Olive Mount Chord between the Port of Liverpool and the West Coast Main Line.
Work could start on the £7.9m project within weeks, involving a quarter-mile stretch of railway linking Bootle with London and Manchester.
Merseytravel will contribute £2.1m to the scheme, with additional support from Network Rail, the North West Development Agency, Merseyside's district councils and the European Regional Development Fund.
The project is seen as key to moving freight in and out of the docks more quickly and easing road congestion. It will also remove the need for freight trains to reverse at Edge Hill, slashing rail times by cutting the need to cross lines into and out of Lime Street at Edge Hill. The line has been closed for 20 years.
Neil Scales, chief executive and director general of Merseytravel, said: "This rail freight link will create a fast route into the port, allowing it to expand and create more employment and it will ease both congestion and pollution through the ability to transfer increased amounts of container cargo from road to rail."
The Port of Liverpool, owned by Peel Ports, handles 34m tonnes of freight annually from over 100 countries.
The project is due for completion by the end of the year.