South Asia's biggest airshow kicks off in India on Wednesday, where global armament firms will be vying for multi-billion dollar contracts from the world's biggest importer of weapons.

India launched the biannual Aero India event in 1996, three years before a mini-war with Pakistan prompted New Delhi to go on a global shopping spree for tens of billions of dollars worth of hardware to equip its million-strong military.

A total of 78 countries have confirmed their attendance, while companies from 27 of them will showcase their latest products at the five-day show in Bangalore, the hub of India's aviation, space and IT industries.

India's state-run Hindustan Aeronautics Ltd (HAL), which signed a deal with Russia in 2010 worth $30 billion to jointly produce 250 to 300 fifth-generation fighter jets, says it hopes to ink major contracts during the show.

"A number of memorandum of understandings in the pipeline are likely to be signed at the airshow," a senior HAL source said without elaborating.

Seattle-based Boeing last year pipped its rivals to provide India with 37 attack and heavy-lift helicopters worth more than one billion dollars. Negotiations are currently underway.

Such negotiations are not a guarantee of sale in Indian defence deals, which can be excruciatingly slow and are often held up by administrative problems and red tape.

India in February last year chose Dassault Aviation of France as the preferred bidder in a $12 billion deal for 126 fighter jets, but talks are still underway with no progress expected this financial year.

Other deals still awaiting a green light include a $600 million contract to supply 197 helicopters to the Indian army, which was scrapped in 2007 after being awarded to the European manufacturer Eurocopter.

The helicopter unit of aerospace giant EADS in 2010 resubmitted a bid for the same deal, with Russia's Kamov also in the running.

The United States will provide the largest contingent of companies at the show, with 67, marking growing ties between the two countries, the chief organiser said in New Delhi.

France, Israel and Russia -- India's biggest arms supplier -- also have a large presence at the show, said India's Defence Production Secretary R.K. Mathur, adding that neighbouring Pakistan had not been invited.

Deadly border tensions flared last month following exchanges of fire in disputed Kashmir which left five soldiers killed on both sides of the highly militarised frontier.

Mathur said China, which fought a brief but bitter war with India over a border dispute in 1962, was likely to attend.

"China has been invited for the show as a formal letter has been sent to them," he said.

Israeli state-run armament firms are scouting to sell unmanned aerial vehicles to bolster India's modest fleet of surveillance drones, some of which are used in the country's struggle against Maoist rebels.

The Stockholm International Peace Research Institute in March 2011 said India received nine percent of global arms transfers from 2006 to 2010, making it the world's largest importer of weapons.

Russian armaments accounted for 82 per cent of Indian military imports, the global arms transfer monitor said.