General manager of insurance and investments Therese Singleton said AMP had covered the tax owed by investors since the fund launched in 1996. It has $502 million under management.

"The importance of this to investors is that they are better off, both because of the increased account balances as well as the benefit of compound interest on those balances over many years," she said.

"Furthermore, AMP is not seeking to recover any of the tax payments made on behalf of investors."

She said the units were being repriced down to reflect the tax provision but said the difference was not big and any effect on members’ individual balances would depend on their circumstances.

"There is no significant change to unit prices for investors in the fund (which is closed to new investors) and all other benefits of the scheme remain on an ongoing basis, including loyalty bonuses."

AMP sent a note to advisers telling them that it was working through its investment information ahead of the Financial Markets Conduct Act deadline of December 1.

"This has involved a detailed analysis and review of all products and legal and registry alterations that need to be made to ensure the products are compliant with the new regime."

The AMP notice said it would be important for advisers to understand what was happening in case clients raised any queries with them about the change.

AMP is also considering whether the personal retirement plan should be moved into the PIE regime.

"There is some complexity that needs to be resolved, but we see this as worth pursuing given the associated benefits to investors."