India was on Friday set to open rival bids from France's Dassault and the Eurofighter consortium, which are competing over a multi-billion contract to provide 126 fighter jets.
The deal to supply war planes to fast-developing India has been fiercely fought over for four years, and the opening of the bids will start the final phase of the decision-making process.
"Negotiations with the (two) firms will start after opening the bids on November 4," Air Marshal D. Kukreja said at the weekend in Bangalore, the hub of India's aviation industry.
"Whatever is beneficial to the country, we will choose," he added.
A meeting was due to start at 0900 GMT.
India in April pulled a surprise by cutting out US bidders Boeing and Lockheed Martin -- much to Washington's disappointment -- as well as dropping Sweden's Saab AB and the Russian makers of the MiG 35 from the race.
"The final outcome will not be known immediately except perhaps an indication of whom we may prefer," retired general Afsir Karim, an expert on Indian arms procurement, told AFP on Thursday.
"A price negotiation committee will finally determine the winner," he said.
Dassault's Rafale plane and the Eurofighter Typhoon have both been in action over Libya in recent months during the international operation to enforce a no-fly zone and protect civilians from Moamer Kadhafi's forces.
James Hardy, Asia-Pacific editor of Jane's Defence Weekly, said the contract was "the single biggest competition in the global defence aviation industry at the moment."
"Both aircraft... are coming off successful performances as part of the NATO air campaign in Libya," he said. "Failure here would be a major blow after both made substantial investment in promoting their platforms in India."
A source for the French group, who declined to be identified, said last week that the decision "could be settled in one day or it could take months if the (price) gap is narrow."
Dassault's rival, Eurofighter, is produced by a consortium of Britain's BAE Systems, Italy's Finmeccanica and the European Aeronautic Defence and Space Company (EADS).
The contract is for the outright purchase of 18 combat aircraft by 2012 with another 108 to be built in India with options to acquire more.
Such a large order attracted strong lobbying during visits to India last year by US President Barack Obama, French President Nicolas Sarkozy, British Prime Minister David Cameron and Russian President Dmitry Medvedev.
India, the biggest importer of military hardware among emerging nations, issued the request for proposals in 2007 and trials of aircraft from the six companies competing for the deal began a year later.
The procurement of the fighter jets is a key part of India's military upgrade programme, aimed at securing its borders against rivals Pakistan and China.