In a regulatory filing, the airline said that Raghavan has resigned from the services of United Breweries (Holdings) Ltd with effect from the close of business hours on July 31.
"Consequently his secondment to Kingfisher Airlines Ltd has simultaneously come to an end and he has ceased to be the company secretary and compliance officer of Kingfisher Airlines Ltd after the close of business hours on July 31, 2015," the filing said.
Bogged down by mounting debt and operational issues, the Vijay Mallya-owned Kingfisher Airlines was grounded in 2012 after aviation regulator Directorate General of Civil Aviation (DGCA) cancelled its licence.