New Delhi, April 28 (IANS) The massive glitch in Air India's passenger services system on Saturday continued to have its impact, as around 137 flights of the national carrier were set to delayed by over three hours each on Sunday.

The average delay would be around 197 minutes per flight, said an airline spokesperson.

The trouble began after Air India's passenger services system server was affected with a glitch while undergoing scheduled maintenance early Saturday. 

As many as 149 flights of the airline group operated by Air India, Air India Express and Alliance Air were delayed on Saturday and thousands of passengers were affected.

The airline operates 470 flights per day while the Air India Group provides 674 flight services.

Once an aircraft gets delayed in the first sector of the route it travels, it is bound to be delayed in subsequent sectors. An aircraft generally goes from one sector to another during the day. 

Air India's passenger services system server is operated by SITA, a global airline IT major.