As many as 14 consortia, including those of L&T, IL&FS and HCC, have expressed interest in the new underground section of metro.
Reliance Infrastructure (RInfra), which developed the first line of transport system in the city, has stayed away.
The proposed Rs 23,000-crore underground line will link Colaba in the south to Seepz area in the north of Mumbai.
Anil Ambani-led RInfra has completed the initial phase of the first metroline connecting Versova-Andheri in the north west to Ghatkopar in the north-east of the metropolis.
Metro One, built on the BOT (build-operate-transfer) model, is a fully elevated system while the proposed line will be fully underground.
While RInfra officially declined to comment, sources said the firm stayed away from the bidding process as the project is being awarded on an EPC (engineering, procurement and construction) basis and not BOT model.
The 14 consortia are: Afcons-KMB, CEC-ITDCEM-TPL, CTCEG-PIIPL, Dogus-Soma, IL&FS-CR25G, JKumar-CRTG, L&T-STEC, Mosmetrostroy-Hindustan Construction, OHL-SKE&C, Pratibha Industries-GDYT consortium, Sacyr-CMC-Essar, Salin Impregilo- Gammon, Strabag-AG-Patel and Unity-IVRCL-CTG.
Last September, when the Government first floated the tenders for the project, it received lukewarm response, leading to tweaking of bidding norms.
Mumbai Metro Rail Corporation (MMRC), the project operator owned by state-run MMRDA, had invited bids for the 32.5-km long underground corridor running from Cuffe Parade to Seepz area in the suburbs with 26 stations.
"Evaluation of the bids is expected to be completed within a period of 90 days," Mumbai Metropolitan Region Development Authority (MMRDA) said in a release here today.
The project, which has received key regulatory clearances, was first proposed as an elevated system but was later switched to underground, and slated to be commissioned in six years after beginning of the work.
Initially, it was planned to commission in FY19.