- Shares in Credit Suisse have fallen sharply in recent days after it said it had found "material weakness" in its financial reporting.
- There are concerns that Credit Suisse shares could continue to plummet, after they fell 24% on Wednesday.
Switzerland's biggest bank, UBS, is reported to be in advanced talks to buy all or part of its troubled rival Credit Suisse.
Shares in Credit Suisse have fallen sharply in recent days after it said it had found "material weakness" in its financial reporting.
An emergency $54bn (£44.5bn) lifeline from the Swiss National Bank has not resolved the issue.
Regulators are trying to facilitate a deal before markets reopen on Monday.
There are concerns that Credit Suisse shares could continue to plummet, after they fell 24% on Wednesday.
This prompted a general sell-off on European markets, and fears of a wider financial crisis.
The Swiss government held an emergency meeting on Saturday night, but so far there has been no official statement on the progress of the negotiations.
UBS is said to have asked the Swiss government to cover about $6bn (£4.9bn) in costs if it were to buy Credit Suisse, according to sources quoted by Reuters.
Any deal may also result in significant job losses.
The problems have coincided with the failure of two lenders in the US - Silicon Valley Bank and Signature Bank - raising fears over the health of the banking system
Credit Suisse, which was founded in 1856, has faced a string of scandals in recent years, including money laundering charges.
It reported a loss of 7.3bn Swiss francs ($7.9bn; £6.5bn) in 2022 - its worst year since the financial crisis of 2008 - and has warned it does not expect to be profitable until 2024.
UBS, however, made a profit of $7.6bn in 2022.
As well as being a domestic bank with 95 branches, Credit Suisse has a global investment banking operation and manages the assets of rich clients.
It is one of 30 banks worldwide deemed too big to fail because they are of such importance to the international banking system.
At the end of last year Credit Suisse had a global staff of 50,480, including 16,700 in Switzerland, though 9,000 jobs were to be axed, the Swiss broadcaster SRF reports.