Tata Group-promoted Air India said on Thursday that Alliance Air is no longer its subsidiary.
In a tweet, the airline said: "Passengers holding tickets of Air India with a 4-digit flight number starting wiith '9' or 3-digit flight number starting with '9I' may please be informed that these bookings belong to Alliance Air.
"Bookings or Queries related to Alliance Air will not be handled by Air India from 15 April, 2022."
Last year, Tata Group bought the debt-ridden state-owned Air India from the Central government by placing a bid of over Rs 18,000 crore at an auction.
On January 27, 2022, it took over the full control of the airline.
(With inputs from IANS)