India has asked France's Dassault Aviation SA to stick to the original price tag for fighter jets or risk losing one of the world's biggest military aircraft deals, the Times of India reported on Tuesday.

Talks on the proposed purchase of 126 Rafale planes have been ongoing for more than three years to resolve differences over pricing as well as local assembly. The deal is back in focus as Prime Minister Narendra Modi visits France this week.

The deal was initially worth $12 billion but is now widely estimated to have jumped to $20 billion, primarily because of the implications of building some of the jets in India.

The Times quoted an unidentified Indian official as saying Dassault wanted to raise the price to cover the increased cost of local production, and that any such escalation could be a deal-breaker.

A defense ministry spokesman was not immediately available to comment on the report. Dassault was also not available.

Under terms of the contract, 18 of the planes will be sold ready-to-fly while the rest will be assembled at an Indian facility as part of a government effort to build a domestic military-industrial base.

The price of the jets was set to increase substantially because the French firm had calculated a rise in hours required to make the jets at the factory of Hindustan Aeronautics Ltd in Bengaluru, the newspaper said.

"Dassault should relent, become fully compliant to the request for proposal and stand 100 percent by its original offer. It can live with a slightly lesser profit margin," the official was quoted as saying.

The two sides have also wrangled over the issue of guarantees for local production of the aircraft, which the newspaper said they were trying to work out. It said, under a new proposal, Dassault will not be liable for penalties if Hindustan Aeronautics failed to deliver the planes on time.

India conducted a global tender in 2007 for the planes after a domestic program to build combat aircraft made slow progress. The Rafale was chosen in 2012 over rival offers from the United States, Europe and Russia.

In a major setback for India's ballistic missile program, a homemade interceptor missile has reportedly failed a crucial test, reports said on Tuesday.

The Advanced Air Defense interceptor missile, developed by the state-owned Defense Research and Development Organization, was fired from the Wheeler Island off the coast of the eastern Indian state of Odisha on Monday.

But the missile, weighing 1.2 metric tons, failed and plunged into the Bay of Bengal soon after being fired for the 10th time since its inception.

"It took off as planned but did not reach the target. We are analyzing the data," test range director MVKV Prasad was quoted as saying.

Reuters - Xinhua