What sort of bank will Westpac and St George be?

It will have 10 million customers, which is roughly half of Australia’s population. Crucially, it will have Westpac’s AA rating, rather than St George’s A. At the time of the merger announcement, it was envisaged as having a combined market capitalization of A$66 billion ($477 billion), although an improvement in the St George share price since then had increased that figure at the time of writing.