Metro Bank has struck a deal to raise extra funds from investors that it said will secure its future.
The deal was announced late on Sunday after days of intense speculation about the bank's financial position.
The Bank of England reportedly asked larger lenders if they were interested in buying Metro, while banks were said to be eyeing up some of its assets.
But on Sunday, Metro Bank said it had raised £325m in new funding, as well as refinancing £600m of debt.
Metro's chief executive, Daniel Frumkin, said the deal marked "a new chapter" for the troubled bank.
Metro Bank's shares had slumped last week after reports suggested it needed to raise cash to shore up its finances. Its share price rebounded on Monday in response to the deal.
However, Simon Samuels, a former managing director at Barclays and Citi, told the BBC's Today programme that while the financing bought Metro Bank some time, it did not address the "fundamental challenges" of the bank's strategy of focusing on High Street branches which was "very expensive".
While many banks have been closing branches and shifting to online banking - which accelerated during the Covid pandemic - Metro continues to focus on bricks and mortar.
"Essentially, Metro finds itself with an unsustainable cost base," he said, adding that he thought Metro's strategy "has got little chance of succeeding in the long run".
"Eventually [Metro Bank] may end up being part of a larger group."
The bank has insisted all along that its finances remain strong and it continues to meet all regulatory requirements.
But under the deal announced on Sunday, Colombian billionaire Jaime Gilinski Bacal will become Metro Bank's controlling shareholder with a 53% stake.
His firm, Spaldy Investments, will sink £102m into the bank.