"This is consistent with how we provide motor vehicle, home, commercial and travel insurance using a range of specialist insurance partners."
OnePath Life policyholders in New Zealand would continue to receive the cover they held under the terms of their policies and it was intended all staff involved would be offered similar roles with Cigna or ANZ.
Cigna is a global health service company with 95 million customers and more than 40,000 employees worldwide.
In New Zealand it offers insurance products online and through direct marketing and also provides insurance products for partner companies. Cigna has been one of ANZ's insurance partners for more than 20 years.
The sale is subject to regulatory approval and is expected to be completed in 2019.
Last September ASB's parent company, the Commonwealth Bank of Australia said it had agreed to sell its life insurance businesses in New Zealand and Australia to AIA.
As part of that transaction, ASB said it would enter into a 20-year distribution agreement with Sovereign and AIA for the provision of Sovereign and AIA life insurance products to its customers in New Zealand.