Macquarie Media chairman Russell Tate has written to advertisers promising a review of Alan Jones' Breakfast Show on 2GB and 4BC after more than 100 brands distanced themselves from the radio network and the shock jock.

Macquarie has been grappling with a backlash from advertisers following comments made by Jones on-air in August that New Zealand Prime Minister Jacinda Ardern should have a sock shoved down her throat.

Alan Jones has publicly apologised for his remarks to New Zealand Prime Minister Jacinda Ardern. Credit:Sydney Morning Herald

In a letter sent on Friday to clients of the radio station, Mr Tate said these comments "fell below the community standards expected of us as [a] broadcaster".

"This incident has brought into sharp focus the need for all Macquarie Media broadcasters to ensure that the debate they bring to the microphone and the words they use are, at all times, respectful and reflect the standards expected today by our listeners, our clients, and the wider community," he said.