The bank has signed for Fiserv's Corillian Online and Voyager offerings for the "online transformation program", which will also cover its St George and Bank SA businesses.

Westpac - which last year said it would standardise core banking on the legacy Hogan platform at recently-acquired St George - is understood to have sent out an RFP running to hundreds of pages as it bids to play catch up online with rival CBA.

Fiserv and Westpac say they will collaborate to deliver a customer-centric design, providing a multi-lingual, customisable user interface and a focus on mobile access. The vendor is also planning to establish a technology centre of excellence in Sydney, housing strategists and developers.

Bob McKinnon, group executive, technology, Westpac Group, says: "Today we serve more than two million active online customers and expect this channel to continue to grow."

Meanwhile, Fiserv today reported second quarter net income of $127 million, a nine per cent fall on the same period the previous year. Revenue rose slightly, from $1 billion to $1.02 billion.