The Finance Sector Union (FSU) reports it's been notified by the Westpac Group it will be shutting down or merging dozens of branches.

The financial institution's Dubbo branch is one of eight slated for a process of "co-locating", with it to move in with St George down the block in September, a list published by the union shows.

Westpac has confirmed to the Daily Liberal it is proposing "co-locating" eight branches in regional areas, but has not provided the exact sites.

It also confirmed it was "working through proposed changes" for "potential closures" at 40 locations, 39 of which were metro, but said the locations were not confirmed.

The FSU claims the closures would affect the jobs and livelihoods of 165 staff members, and involved the Westpac, St George, Bank SA and Bank of Melbourne brands.

The "co-branding" process will mean one branch will close with customers urged to go to another Westpac Group site where two bank brands will trade from the same branch, the union says.

FSU national secretary Julia Angrisano slammed the bank's proposal.

"Westpac is deserting its customers and its staff by closing branches to shore up its profits," she said.

"This shutdown of so many branches is of major concern to our members and will impact on a large number of staff, banking customers and businesses around Australia.

"Westpac will claim the decision to close branches is because consumers are moving to internet banking but that's not the case.

"If these branches were making large profits for the bank they would not be closing."

Westpac Group reported it would be one of the first banks to use its a multi-brand presence under the model proposed, which provided an important community service particularly in regional areas.

A Westpac spokesperson said there had been a "seismic shift toward digital and cashless banking" and declining foot traffic in bank branches, particularly in urban and metropolitan areas.

"When we do close a branch, it is not a decision we take lightly," the spokesperson said.

"We take into consideration customer usage, location and proximity to other banking services.

"We are currently in consultation with our people regarding branches in metro areas with low utilisation, where there is a nearby branch within five kilometres and where customers are preferring the convenience and increased safety of contactless, cashless and digital channels.

"Branches will continue to remain an important service option, especially in areas that have high customer usage."

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