By Agence France-Presse
The agreement has been passed to the US Congress for approval, but if no US lawmaker raises an objection the contract is expected to go ahead.
Boeing and Indian partner Tata have begun to produce Apache fuselages at a plant in India, but Tuesday's approval concerns a direct sale of finished products from US manufacturers.
The lead contractors are US arms, aviations and engineering giants Lockheed Martin, General Electric and Raytheon.
In addition to aircraft, the contract includes night vision sensors, GPS guidance and hundreds of Hellfire anti-armor and Stinger air-to-air missiles.
"This support for the AH-64E will provide an increase in India's defensive capability to counter ground-armored threats and modernize its armed forces," the US Defense Security Cooperation Agency said, in a statement.
"India will have no difficulty absorbing the helicopters and support equipment into its armed forces. The proposed sale of this equipment and support will not alter the basic military balance in the region."