Fitch plans to withdraw its ratings of IAG and subsidiaries next month.

Fitch Senior Director John Miles told insuranceNEWS.com.au the agency made a business decision not to rate the insurer.

He says IAG does not issue much debt to institutional investors that use ratings.

Fitch had given IAG and IAG New Zealand an insurer financial strength rating of AA- with a stable outlook. The insurer had not solicited the ratings.