Lockheed Martin has won a $375 million contract for bespoke hardware and software for India’s acquisition of 24 Sikorsky MH-60R anti-submarine warfare helicopters.

“This modification provides non-recurring efforts to design and develop unique hardware and software for the Multi-Role Helicopter MH-60R development programme for the government of India,” says a US Department of Defense contract announcement.

In May, Lockheed’s Sikorsky rotorcraft unit signed a $905 million contract with the US Navy to provide 24 MH-60Rs to the Indian navy via the US government’s Foreign Military Sales (FMS) process.

The $905 million contract was far less than the original notice, which valued the deal at $2.6 billion.

At the time of the May award, Tom Kane, director of Sikorsky naval helicopter programmes, said the $905 million would cover production of the helicopters, but that additional work would be necessary for “unique modifications and systems”.

The MH-60R is New Delhi’s second acquisition of a major US Navy anti-submarine warfare platform, following its acquisition of the Boeing P-8I Neptune in a 2009 deal.

In Indian navy service the P-8I is understood to feature several Indian-produced systems, such as Bharat Electronics identification friend or foe equipment, and a locally developed datalink.