India and Israel have finalised a $1bn deal for the supply of three Phalcon airborne early warning radar systems to India, both sides say.
Delivery will be within 44 months of an advance Indian payment
The Israeli-made system, fitted on Russian Ilyushin aircraft, will be delivered within 44 months of an Indian advance payment.
Israel's cabinet had approved the transaction last Sunday and it was signed in Delhi on Friday.
Rival Pakistan has previously accused India of a weapons shopping spree.
The joint secretary of India's defence ministry, CR Mahapatra, signed the accord with Israel Livnet, the vice
president of the Israeli Aircraft Industrial Corporation.
Indian defence ministry spokesman Amitabh Chakravarty said Israel would buy Ilyushin-76 cargo aircraft from Uzbekistan.
These would be fitted with new engines in Russia then mounted with the Phalcon system in Israel.
Phalcon is a competitor of the US-made Awacs system.
"The Phalcon deal is the biggest leap forward yet for Israeli military exports," said Amos Yaron, director of the
Israeli defence ministry.
Israel and India signed a preliminary agreement last October after the United States lifted objections that the sale might endanger peace on the subcontinent.
Defence analysts say the Phalcon system will give India a greater edge in conventional weaponry over its regional rivals, China and Pakistan.
Phalcon can detect low-flying objects from a distance of hundreds of kilometres, day or night, in all weather conditions.