The Indian Government has reportedly shortlisted Larsen & Toubro (L&T) and Pipavav Defence & Offshore Engineering Company for a Rs600bn ($9.56bn) contract to construct six conventional submarines in the country.

An unidentified senior defence ministry official was quoted by Business Standard as saying: "Project 75i, as we call it, is for purchasing six next-generation submarines with air independent propulsion (AIP) system[s] for the Indian Navy over the next seven to eight years. It can fire both torpedoes and missiles.

"L&T and Pipavav have been shortlisted. This was based on the recommendations from a high-level committee that had inspected the shipyards of several companies, both private and state-run, to zero in on the potential candidates."

"The new submarines will feature advanced detection range and combat management systems."

The Indian Ministry of Defence formed a committee to identify shipyards that are capable of building submarines, during a Defence Acquisition Council meeting last year.

To date, the committee has selected L&T’s Katupalli yard and Pipavav unit. This decision was made following reviews on several public and private shipyards, including Garden Reach Ship-Builders, Hindustan Shipyard, Goa Shipyard, Mazgaon Docks (MDL) and ABG Shipyard.

The tender will include technology partnerships with foreign collaborators that have substantial manufacturing in India.

The AIP systems will help submarines to stay submerged for longer periods, unlike conventional diesel-electric submarines that have to surface every few days.

Scheduled to be built on the lines of the predecessor P75 Scorpene production line at MDL, Mumbai, the new submarines will feature advanced detection range and combat management systems, as well as better sensors for optimum performance and a weapon system that includes torpedoes and missiles.