Government is yet to be approached by United States company, Railnet International, which has indicated its willingness to construct a US$11 billion railway line running from Zambia's Copperbelt Province to the port of Beira in Mozambique via Harare.
The investment envelope includes the cost of locomotives and wagons.
Feasibility studies were expected to begin in the next six weeks and would be followed by detailed engineering design for the project on the Zambian side.
While Railnet says it has signed an agreement for the project in Zambia, the firm is yet to approach the Zimbabwe Government.
But Transport and Infrastructural Development Minister Joel Biggie Matiza said Zimbabwe will benefit from investment if t sails through.
"We have heard about that project but they have not yet come to us officially. We cannot say much at the moment until we have some discussions with them," said Minister Matiza.
Railnet chief executive officer Mr Donald Kress was quoted in the media saying his railway development and construction company was in talks with governments in the three countries and signed an agreement to start feasibility studies in Zambia.
"We have a group known as Magcor International and their CEO has arranged financing through a group of investors," Kress told Reuters on Sunday following the signing of an agreement on Saturday.
"Until we have signed a contract with the investors, they have requested to remain anonymous," Kress said in an interview.
Transport and Communication Permanent Secretary Misheck Lungu signed the agreement on behalf of the Zambian government.
Mr Lungu said the project would enable business including mining companies in Africa's second-largest copper producer to transport bulk cargo by railway instead of using roads.
He said Railnet would operate the modern railway for a number of years and hand it over to the Government after recovering its investment from the profit made.
Zimbabwe is looking for investors in the rail sector to facilitate speed movement of goods and people.