Westpac Banking Corp, Australia's third largest bank by market capitalisation, said on Monday it would raise A$750 million ($488.1 million) in an Additional Tier 1 (AT1) capital transaction. The notes will be issued at $A100 each and potential investors have been told the interst margin be between 3.10% and 3.3%, according to a Westpac statement. Australia's prudential regulator said in September it would review the rules around AT1 bonds, which were impacted by the collapse of Credit Suisse in March, to determine they were still fit for purpose.