Further detailed studies will be completed in August, and bids will be invited for the contract to build the line in December. Construction will start next year and take around three years to complete.
Bids will be invited in June for the contract to build the first two stations, Magdalena and El Labrador, and for a maintenance and training centre.
The 15-station line from Quitumbe in the south to El Labrador in the north has a budget of $US 1.4bn. The Inter-American Development Bank will finance $US 200m, while the Andean Development Fund and European Investment Bank will each provide $US 250m.