Shares of InterGlobe Aviation, which operates IndiGo, slipped nearly 4% in early trade on Thursday as investor sentiment was dented after the Competition Commission of India (CCI) ordered an investigation into the airline’s conduct during a major operational disruption in December 2025. The CCI has directed its Director General to submit an investigation report within 90 days.

Ending its three-session gaining streak, IndiGo shares fell as much as 3.65% to hit an intraday low of ₹4,782.45 on the BSE after a weak opening at ₹4,835.15. The aviation heavyweight had gained nearly 8% over the previous three trading sessions.

At the time of reporting, the airline’s stock was trading 2.1% lower at ₹4,858.50, with a market capitalisation to ₹1.88 lakh crore. The counter is down 22% from its 52-week high of ₹6,225.05 touched on August 18, 2025, while it had hit a 52-week low of ₹4,161.00 on February 17, 2025.

In a 16-page order dated February 4, the competition watchdog alleged that passengers whose flights were cancelled at short notice were effectively left without meaningful alternatives. Many were forced to either accept cancellations or arrange travel on their own at substantially higher fares, the regulator observed.

“It is observed that passengers who had booked tickets were left with no real choice but to accept last-minute cancellations. Further, passengers were left to seek alternatives on their own at significantly higher prices,” the CCI said in its order.

For IndiGo, the troubles began on December 2, when the airline, which commands over 60% of the domestic market share, started cancelling flights even as passengers faced inordinate delays, at times stretching up to seven hours. The crisis led to around 2,500 flight cancellations and more than 1,800 delays during the first week of December. By December 5, the situation spiralled further in ways even IndiGo had not anticipated. On that day alone, more than 1,600 of its scheduled 2,200 flights were cancelled, turning air travel into a nightmare for thousands of passengers.

The CCI said IndiGo’s cancellation of a large number of flights, forming a sizeable share of its scheduled capacity, may have resulted in an “artificial scarcity” in the domestic aviation market during the peak travel period. Such actions, when undertaken by a dominant player, could amount to restricting the provision of services under Section 4(2)(b)(i) of the Competition Act, it added.

The regulator further noted that IndiGo’s market dominance may have left consumers “locked in,” limiting their ability to switch to alternative carriers and potentially violating provisions related to unfair or discriminatory conduct under Section 4(2)(a)(i) of the Act.

The probe follows a complaint filed by Bengaluru-based passenger Kartikeya Rawal, who alleged that his IndiGo flight was cancelled just hours before departure without a viable alternative. According to the complaint, he was compelled to rebook another IndiGo flight at nearly ₹17,000, more than double his original ticket price of ₹7,173, as other options were unavailable.

Notably, IndiGo has already faced regulatory action from the Directorate General of Civil Aviation (DGCA), which imposed penalties totalling ₹22.20 crore and issued warnings to CEO Pieter Elbers and other senior executives for regulatory lapses.

(DISCLAIMER: The views and opinions expressed by investment experts on fortuneindia.com are either their own or of their organisations, but not necessarily that of fortuneindia.com and its editorial team. Readers are advised to consult certified experts before taking investment decisions.)