Shares of InterGlobe Aviation Ltd, promoters of budget carrier IndiGo, bucked the broader market trend to trade lower on Tuesday. At 2.50 pm, the stock was down 2.1% at ₹1,419.50, having touched an intra-day low of ₹1,389.

The Sensex was at 40,784.84 points, down from its intra-day high of 41,120.28, but up nearly 0.3% from previous close.

On Monday, the Directorate General of Civil Aviation (DGCA) warned IndiGo that the airline's efforts to modify older Pratt & Whitney (P&W) engines installed on Airbus A320Neo aircraft were not satisfactory, which means a significant portion of its fleet could be grounded if the carrier failed to meet a 31 January deadline.

“We may find ourselves in a situation in which we remain saddled with a large number of aircraft with unmodified engines and operating on a schedule approved by us," the DGCA said, while adding that the grounding of aircraft would be a sub-optimal solution.

IndiGo has 98 aircraft of the A320Neo family, comprising 91 of A320Neos and seven planes A321Neos, which are all powered by P&W engines. Of these, one of the two engines fitted in 23 aircraft have been modified.

The airline recently took delivery of an A320Neo family plane days after the DGCA issued a directive. The regulator said that for every new A320Neo aircraft that IndiGo adds to its fleet hereon, it would have to ground a similar aircraft with unmodified engines.

On 1 November, DGCA had directed IndiGo to replace P&W engines with modified low pressure turbines (LPTs) on 97 Airbus A320Neo aircraft by 31 January, following a series of engine incidents.