Airbus has announced the biggest plane deal in its history as it accepted a massive order for 500 aircraft from India’s largest carrier, Indigo.

The multibillion-dollar deal is the largest ever for aircraft, eclipsing Air India’s recent purchase of 470 aircraft earlier this year, as India’s two largest carriers plan a sharp expansion in regional travel demand.

The deal follows months of negotiations.

“This is just the beginning, there will be more to come. With the growth of India (and) the growth of the Indian aviation market… this is the right time to place this order,” said IndiGo CEO Peter Elbers at a press conference.

The aircraft will be delivered between 2030 and 2035.

Efforts by Indian carriers to keep pace with the world’s fastest-growing aviation market have led to record industry declines, even as manufacturers struggle to meet production targets.

Indian companies now have the second-largest order book, with a share of more than 6% of the industry backlog, behind only the United States, according to a June 1 Barclays report.

IndiGo, which accounts for nearly 60% of the Indian domestic market, was widely expected to retain Airbus as its single-aisle jet supplier to extract further economies of scale.