Thousands of Air India passengers were stranded at airports across the world on Saturday, after a software "glitch" left those travelling with the state-run airline unable to check in, officials said.

More than 80 domestic and international flights were delayed for six hours because of a problem with the company's check-in software that brought operations to a halt, causing further flight delays across the globe.

"Our check-in software experienced a glitch following a routine software upgrade. It was resolved after six hours," Air India spokesman Praveen Bhatnagar told AFP.

Bhatnagar said most of the delays were on its domestic circuit and they were "doing everything possible to clear the backlog".

There were no flight cancellations and the airline expects operations to be back to normal by early evening, the spokesman said.

India's aviation industry is in choppy waters after one of the country's largest private carriers, Jet Airways, last week halted its operations indefinitely following refusal by lenders to pay it cash to run day-to-day operations.

The state-owned loss making Air India operates more than 450 fights a day across the globe, with a majority of them domestically.

Hundreds of furious passengers took to social media to complain about the widespread disruption, posting pictures and videos of passengers waiting at check-in counters.

"Thousands stranded at the airport for over 3 hours. No updates. No one to talk to. Terrible service," a traveller posted on Twitter from Delhi International airport.

Saturday's software malfunction is a repeat of a similar outage in June last year that caused flight delays globally.