Cbus is conducting an open market Request for Proposal (RFP) for the provision of custody services to the fund.
NAB Asset Servicing has provided Cbus with custody services since 1993, with periodic service reviews cementing the custodian's long-term relationship.
Cbus said it was the first full RFP since the relationship had commenced 20 years ago.
Cbus executive manager of investment management Trish Donahue said it was important that the fund review its service providers to ensure members were receiving the best possible deal and that service delivery was keeping up with the changing needs of the fund and its sector.
"Cbus and NAB Asset Servicing have a long-standing relationship and NAB Asset Servicing is highly regarded in the sector for its custody services," Donahue said
"In the current rapidly changing regulatory environment and in light of the major investment review recently undertaken within the fund, Cbus is using the RFP process to test the market and see who can best meet our growing requirements into the future," she said.
The review will be conducted over the next few months with a decision expected early in the new financial year.
Donahue announced the appointment of David Vaughan to conduct the RFP on behalf of the fund.
Vaughan has over 25 years experience consulting to institutional superannuation funds and funds management organisations.
Superannuation fees have continued their multi-year decline, as fund consolidation and index investing deliver scale efficiencies for members.
Super funds demand fast passage of payday super laws, while small business advocates warn of cash flow pressures and compliance risks.
The superannuation industry could move faster on personalisation, according to MLC, and the fund has identified three core areas where it will be focusing its personalisation efforts over the next 12 months.
The Actuaries Institute has released a framework to help super funds deliver affordable guidance and advice to millions approaching retirement.