Warsaw City Council has allocated a budget of Zlotys 3.17bn ($US 820m) for the second phase, but the two lowest-priced offers accepted by Warsaw Metro have a combined cost of just Zlotys 2.21bn.
Five bids were submitted for the contract to build the 3.4km western extension from Rondo Daszyńskiego to Wolska, Moczydlo, and Ksiecia Janusza, and Gülermak, Turkey, has been chosen as preferred bidder having submitted an offer of Zlotys 1.14bn.
The 3.1km eastern extension from Dworzec Wileński to Swedzka and Targowek will be constructed by Astaldi, which submitted an offer of Zlotys 1.07bn, the lowest of four bids for this section.
Working as part of the AGP Poland consortium, both Astaldi and Gülermak were involved in the construction of the initial 6.5km section from Dworzec Wileński to Rondo Daszyńskiego, which opened in March. Like the initial phase, the two extensions will run completely underground and construction is due to be completed in the first half of 2019.