IndiGo, the biggest customer for Airbus Group SE’s A320neo jets, is considering slowing deliveries of the single-aisle aircraft to give supplier Pratt & Whitney more time to upgrade the model’s engines. The Indian carrier may seek the delivery slowdown “to allow Pratt & Whitney to catch up on the production of upgraded engines,” InterGlobe Aviation Ltd., which operates the airline, said in its fiscal first-quarter financial statement, without providing details. IndiGo’s A320neo order at Airbus totals 430 planes, with the first aircraft handed over in March. As of May, a further 24 equipped with Pratt & Whitney engines were scheduled for delivery by March 2017. The carrier has said it would consider switching to rival CFM International Inc.’s power plants for later orders. Airbus fell as much as 1.2 percent and was trading down 0.9 percent at 52.12 euros as of 1:32 p.m. in Paris. The stock has dropped 16 percent this year, valuing the Toulouse, France-based manufacturer at 40.3 billion euros ($45 billion). Spokesmen at the company didn’t immediately answer phone calls or e-mails seeking comment. The A320neo program has been held up because the engine built by United Technologies Corp.’s Pratt & Whitney division requires a delay to start up so it can reach the right operating temperature. Airbus and the engine maker have said they’ve devised a fix and are working on an upgrade. IndiGo also said Monday that net income for the three months ended in June fell 7.4 percent to 5.9 billion rupees ($88.6 million), hurt by low fares in a fiercely competitive market. India, where passenger numbers climbed 20 percent last year, offers growth opportunity to carriers with an emerging middle class flying for the first time, but base fares as low as 2 cents have been eroding their margins. State taxes of as much as 30 percent also make jet fuel the costliest in Asia.