The bank says Fed isn’t done with hiking and sees another rate increase next week.
The bank, which is also looking at options for shoring up liquidity, is expected to draw interest from larger rivals, sources said.
Both credit assessors said further downgrades are possible as the bank faces deposit outflows that could affect its liquidity profile and ramps up wholesale borrowing.
The bank's shares fell as much as 25% to hit a record low in European trading after the remark by the chairman of Saudi National Bank.
Founder of the eponymous discount brokerage has seen his wealth drop more this year than any other US billionaire.
The firm says it has sufficient liquidity to handle any volatility and that more than 80% of deposits are insured by the FDIC.
Shares of regional lenders started the week by selling off, with First Republic down 67%, after Friday's collapse of SVB Financial and Signature Bank's seizure by regulators over the weekend.
In a move to shore up confidence in the banking system, the Fed program will provide banks with one-year loans under easier terms than usual.
The FDIC aims to find buyers for the bank's units to enable it to return as much of clients' money as possible.
The bank's customer base of tech startups had become worried and yanked deposits.
