The project will include the construction of new underground stations at Zacisze, Kondratowicza, and Bródno.
Offers will be opened on March 30 and the winning bidder must complete the works within 38 months of contract signing.
Price will account for 60% of the scoring in the bid evaluation process.
The intial 6.5km section of Line M2 from Dworzec Wileński to Rondo Daszyńskiego was inaugurated in March 2015.
Construction is currently underway on a 3.4km western extension from Rondo Daszyńskiego to Ksiecia Janusza and a 3.1km eastern extension from Dworzec Wileński to Trocka.
A further 2km extension from Ksiecia Janusza to Wola Park and Powstańców Sląskich is also planned.