Royal Bank of Scotland (RBS) is preparing to sell off a number of its assets to focus on the core running of the business.
A strategic restructuring review of RBS is set to be published this week along with the firm's preliminary results on Thursday.
It is reported the bank now 68 per cent owned by the government - will create a non-core division for its unwanted assets worth around £250 billion that will be sold of over five years.
In the UK, its high street banking operations under the NatWest and RBS brands is expected to be kept, along with Direct Line insurance.
Worldwide job cuts of as many as 20,000 are also expected, and union officials are already due to meet RBS.
RBS has already announced 2,300 UK job losses - in advance and separate from the strategic review.
Rob MacGregor, Unite national officer for the finance sector, said: "This is already an extremely worrying time for finance workers so it is distressing for those at RBS to hear rumours of more job losses like this.
"Until we meet with RBS today for scheduled talks on the CEO's strategic review, the workers and their union remain in the dark about the bank's intentions."
He also called on the government to ensure job losses and restructuring is "managed in an orderly and humane manner".
Losses and writedowns of as much as £28 billion are due with the results later this week.
RBS is also expected to take advantage of the government's asset-protection scheme, although there has been speculation over how it will be able to afford the costs levied for the insurance protection.
On news of the restructuring, the RBS share price rose 17.10 per cent at 9:05 GMT to the still very depressed price of 22.60p.