New Delhi, Oct. 7 -- The International Air Transport Association (IATA) has asked airlines to negotiate with Adani Airport Holdings Ltd for a longer transition timeline for shifting some international operations from Mumbai airport to Navi Mumbai, after the government deferred the airport operator's plan to cut international departure slots by a third at Mumbai airport.

IATA has asked airlines to use global and Indian slot-allocation guidelines in their discussions with Adani Airport, including provisions aimed at protecting airlines' existing slots, according to an email sent by the industry body to airline chiefs and reviewed by Mint.

Adani Airport, which operates the Chhatrapati Shivaji Maharaj International Airport (CSMIA) in Mumbai...