Boeing has confirmed India’s decision to buy the P-8I long-range maritime patrol aircraft, the largest deal for a weapon system so far between the two strategic partners.

“We are pleased that the government of India has selected the P-8I, making India the first international customer for the P-8,” says Vivek Lall, Boeing Integrated Defense Systems vice president and India country head.

The reportedly $2.1 billion deal will allow India to replace its Tupolev Tu-142 turboprop maritime patrol aircraft, eight of which are in service according to Flight's MiliCAS database. The P-8I was selected over several potential rivals, including the EADS Airbus A319.

“The result of these efforts will bring the Indian navy advanced technology that is unmatched in maritime reconnaissance aircraft, and the reach and capability it needs to defend India's vast coastline and maritime waters," Lall said in a statement.

Boeing plans to hold a press conference on 6 January to discuss further details of the contract. However, Indian media reports say the deal is for eight aircraft, plus options for between a further four and eight. Deliveries will begin in around four years time, according to Indian defence ministry sources in New Delhi.

The P-8I deal follows a $1 billion contract India signed to purchase six Lockheed Martin C-130J tactical transports.

US aerospace manufacturers were cleared to market weapon systems to India by the Bush administration in 2005, and the P-8I quickly emerged as a candidate for the navy's long-range maritime reconnaissance requirement.

Additional reporting by Radhakrishna Rao in Bangalore