Group General Counsel and Company Secretary Peter Horton has left IAG with immediate effect, after the insurer said his behaviour "fell short" of its expectations.

A search for his replacement will commence shortly, IAG said in a statement to the Australian Securities Exchange today.

“The company has concluded that Mr Horton’s behaviour has fallen short of the expectations in IAG’s employee code of ethics and conduct,” CEO and MD Nick Hawkins said.

"This includes the importance of being inclusive and respectful, and we will hold people to account if they fail to meet these expectations.”

Sydney-based Mr Horton was formerly group general counsel and company secretary at QBE, Woolworths and WMC Resources, and spent seven years as Principal Solicitor at BHP Petroleum.

He was appointed by IAG four years ago after three years as TransGrid EM legal, governance and risk.

Last month, IAG announced the appointment of Andrew Collings as an additional Company Secretary, effective November 28, and said Jane Bowd would continue as Company Secretary.