Dávid Vitézy said Fomterv won the contract with a bid of net HUF 850 million.
He said the construction of the tunnel running under the Danube linking the two stations would be a "marked improvement" for the suburbs around the capital, adding that Budapest's railway stations can handle just 42 trains an hour during peak commuter times, when that number should be over 90.
Főmterv has 510 days to complete the environmental impact study and get an environmental permit for the project.