India is close to concluding a contract with the US for acquiring six C-130J Super Hercules transport planes, the first deal between the two countries for military aircraft, defence sources said.

A 'request for details' for the deal was submitted to the US embassy last month, and this was forwarded to the Pentagon so that the deal could be notified to the US Congress, the sources said.

The deal, once approved by the US Congress and New Delhi, will be a one-off contract between the governments of the two countries under Washington's Foreign Military Sales programme.

There will also be an option for six additional Hercules aircraft manufactured by aviation major Lockheed Martin, the sources said.

The sale is expected to be finalised in the next few months, they said.

The Super Hercules aircraft, which can carry a payload of 20 tonnes, are likely to be used for operations by Special Forces and strategic airlifts, the sources said.

The Indian Air Force is currently upgrading its fleet of about 80 Russian-made An-32 medium-lift cargo planes as well as 25-30 Il-76 heavy-lift jets, and officials have said there is a need for an aircraft like the Hercules, which could fit somewhere between the two others.

The Hercules' ability to make short take-offs and landings from rough runways makes it suitable for operations involving Special Forces as well as emergency missions in areas affected by natural disasters, sources said.

Lockheed Martin is also in the race to sell India 126 multi-role combat jets and has offered the P-3C Orion reconnaisance aircraft to the Indian Navy.