NEW DELHI — Global aerospace companies Embraer from Brazil and Lockheed Martin from the United States are offering to expand aircraft manufacturing facilities in India as they pursue an approximately $10.5 billion contract for 60 medium transport aircraft for the Indian Air Force.

Embraer’s C-390 Millennium is competing with Lockheed Martin’s C-130J Super Hercules as India seeks to replace its aging military transport fleet that includes the Soviet-era Antonov An-32.

The formal race for one of India’s biggest military aviation contracts set off in August when India issued a Request for Proposal to five Indian companies setting the stage for the bidding. Global aviation companies are partnering with Indian firms because New Delhi has mandated that while the initial multi role aircraft will be delivered ready to fly, the rest must be built domestically.

With India’s focus on building a local aerospace industrial base, Embraer announced on Oct. 1 that the company and its Indian partner, Mahindra Defence, have identified the central Indian city of Nagpur as a production site for the aircraft if they are awarded the contract.

“Identifying Nagpur as a potential location for an assembly facility is an important step in building a robust, long-term aerospace ecosystem in the country,” said Bosco da Costa Junior, president and CEO of Embraer Defense & Security, in a joint statement with Mahindra.

The two companies said they will progressively integrate Indian aerospace companies into the C-390 Millennium ecosystem to deliver manufacturing, training and lifecycle support.

Lockheed Martin already has a presence in India — the Indian Air Force currently operates 12 C-130J Super Hercules aircraft. The company says the aircraft it is now offering, the C-130J-30 in its Block 8.1.2 configuration, will be more advanced than the ones currently with the air force.

If it wins, Lockheed has said that 12 aircraft would be built in the U.S. and 48 in India in partnership with Tata Advanced Systems Limited, with which it has a joint venture.

The American company already has a manufacturing base in India. It makes key components, including the aircraft’s empennage or tail assembly, locally with Tata.

Winning the contract would mean establishing a bigger industrial footprint in India, Dan Tenney, Lockheed Martin’s senior vice president for global business development and strategy, recently told the Press Trust of India.

“We have a long partnership with Tata that produces components and empennages of the C-130J aircraft. It is a very robust capability that will be expanded in our current bid,” he said. The company has also proposed upgrading the Indian Air Force’s existing fleet of 12 C-130Js.

India has set a requirement of minimum 40% domestic content for the aircraft. Because the country shares long Himalayan borders with rivals Pakistan and China, the aircraft must also be able to operate in high-altitude locations and from temporary or unpaved strips. Besides ferrying troops, vehicles and ammunition, India also uses military transport aircraft for disaster relief and humanitarian assistance. The bids are due by early December, after which the proposals will go through technical evaluation.

Amid its two decade-long push for greater local production and technology transfer, the government wants the mega aviation contract to deepen the country’s defense manufacturing footprint.