Indigo, India’s budget carrier, said that the Airbus SE is not delivering planes fast enough.

The airline is also the biggest customer for Airbus’ best-selling A320neo jets. “The delay in getting planes on time is forcing the airline, operated by InterGlobe Aviation Ltd, to slow down the pace of expansion,” executives said.

“The issue is on the supply side,” Chief Executive Officer (CEO) Ronojoy Dutta said on a conference call with investors on Thursday.

“The reason why we are not growing fast enough is because we are not getting airplanes fast enough from Airbus,” he added.

IndiGo has ordered 430 A320neo jets. It is embarking on an ambitious expansion plan, especially in the international markets, seeking to eventually connect cities such as London with New Delhi. The airline, which is Asia’s largest budget carrier by market value, controls almost half of the domestic market, and is in talks with the European planemaker for another large order.

“IndiGo will not keep adding six planes a month as it was doing earlier partly because Airbus deliveries are delayed by about 3-4 months,” Chief Operating Officer (COO) Wolfgang Prock-Schauer said on the same call.

Delivery schedules are determined in discussions with customers and were confidential, Airbus said in an email.

Earlier on Thursday, IndiGo said it now expects to expand capacity by 25 per cent for the year ending March 31, compared with a an estimate of 30 per cent it made in July. The airline, founded by billionaires Rahul Bhatia and Rakesh Gangwal, also posted its biggest-ever quarterly loss amid fierce competition in India.

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