The second stage of the Metro will extend service from San Miguelito to Tocumen.
There has been some criticism of the bidding process because the government has not publicized a reference price for the work. Bids 20 percent under or 20 percent over that price will be disqualified.
Three consortiums are expected to present bids. They are the consortium formed by Brazilian contractor Norberto Odebrecht and the Spanish company FCC, which built the first line of the Metro for $1.4 billion, a consortium consisting of Mexican company ICA and Spanish construction company ACS, and the consortium consisting of China Harbour Engineering and Construction Company, China Railway Group and the Spanish firm Insolux Corsan.
The bidding process began in September 2014.
The proposals will be judged on technical merits and expected price. The weighting is based on 1,000 points, with the technical part counting for 510 points. The winning bidder will be required to post a performance bond equivalent to 50 percent of the value of the quotation, and the price should include all costs: labor, materials, equipment and related services.