The state-owned airline could face more discontent with around 100 pilots threatening to quit.As many as 23 Air India pilots reported sick leading to cancellation of 10 international flights.

The pilots belonging to the Indian Pilots' Guild (IPG), which has pilots of the erstwhile Air India as its members, are headed for a dispute charging the management today with adopting discriminatory attitude against them and stalling their career progression.

The threat to quit could hit Air India's international operations and comes on the back of cancellation of the 10 flights of its low budget arm "Air India Express" in the last seven days.

The sources said, The Gulf sector remained unaffected but the Kolkata-Dhaka and Chennai-Singapore sectors were hit.

The threat to quit came four days ahead of the launch of a training programme for pilots to fly the Boeing 787 Dreamliners, the first of which is expected to join the airline by December.

In a letter to Air India CMD Rohit Nandan, over 100 pilots, owing allegiance to the IPG said they were "compelled to seek a No Objection Certificate so that we may consider seeking employment elsewhere".

Copies of the letter were also sent to civil aviation minister Vayalar Ravi and other officials, besides the Regional Labour Commissioner, Mumbai.

An Air India spokesperson said, "We have not received any strike notice so far or a notice for NOC formally from the IPG ".

One of the prime grievances of the IPG is the management's decision to train pilots of erstwhile Indian Airlines for the Boeing 787 Dreamliners.

The IPG represents around 200 pilots of the pre-merger Air India, while the Indian Commercial Pilots Association that had gone on strike in April-May this year represents around 1,400 pilots of the erstwhile Indian Airlines.

As IPG sources said, A total of 101 pilots signed the letter claiming they felt "cheated by the management's unfair and discriminatory decisions, leading to a complete stall of our career progression".