Shortt said the bank was looking at which of the 76 recommendations could apply here.
Aegis was started by Sovereign Insurance in 1996 and became part of ASB in 1998. It manages local and offshore investments on behalf of banks, brokers, trustee companies and fund managers.
Adam Boyd, ASB's executive general manager for private banking, wealth and insurance, says the aim of the review is to test whether Aegis can better grow and improve its service to customers within ASB or under new ownership.
Aegis comprises two business, Aegis Ltd and Investment Custodial Services.
The firm says its custodial wrap service offers investors access to some products only available through investment platforms, and at wholesale fees and low brokerage. All portfolio transactions are managed and reconciled by Aegis, which also provides valuation, performance and tax reporting.