Westpac Banking Corporation is raising $500 million through the issue of subordinated notes.
Westpac on Monday said the notes would be offered at an issue price of $100 each.
Group treasurer Curt Zuber said the note issue would strengthen the bank's total capital position.
The offer is expected to open to shareholders, broking firms and institutional investors on July 23 and close between August 16 and 22.
The notes will pay interest in cash, quarterly in arrears.
The interest will be calculated based on the 90-day bank bill rate plus a fixed margin to be determined during the bookbuild process.
The notes will have a fixed maturity date of August 23, 2022.