The firm walked back plans after abandoning a deal to buy robo-advisor Wealthfront.
The ratings agency said that the Swiss bank's restructuring plan entails elevated restructuring and remediation costs.
The overhaul is an urgent attempt to restore credibility at Credit Suisse after a succession of big losses.
The response to inflation by central banks is giving banks a tailwind in lending revenue.
The firm is exploring radical cuts to its volatile investment bank.
Investors are worried about how the bank will cover the cost of a strategic restructuring.
Credit Suisse's top executives and board members are weighing several options as they look to stem the historic stock rout.
The bank is in the midst of electing which businesses to cut, exit or keep.
The Zurich-based bank is reassigning advisors to its Private Banking International unit.
One possibility is that the investment bank ceases to exist as a separate division at some stage.