AMP shares have tumbled after the wealth manager announced it will sell its Australian and New Zealand wealth protection and mature businesses to London-based insurance firm Resolution Life for $3.3 billion.

The company which came under intense scrutiny from the royal commission into the country's financial sector for wrongdoing earlier this year, also said it was contemplating an initial public offering for its New Zealand wealth management and advice businesses in 2019.

The sale value of its Australia and New Zealand wealth protection and mature businesses would amount to $1.9 billion in cash, with a non-cash component making up for the rest.

AMP shares were down 29 cents, or 8.8 per cent, to $3.02 at 1158 AEDT.

The company said it expected to monetise the non-cash consideration over time, without putting a timeline on it.

AMP said it expected the sale to close in the second half of fiscal 2019.

Also, AMP said it has entered into a reinsurance agreement with Zurich-based insurance firm Swiss Re for the New Zealand retail wealth protection portfolio that is expected to release up to $150 million of capital, the company said.

In August, AMP booked its worst first-half profit in 15 years as it set aside cash to compensate customers it sold bad advice, and said that people were still withdrawing money amid a misconduct inquiry.