Shares of First Republic Bank tumbled 13% in premarket trading on Friday as $30 billion in deposits injected by large U.S. banks failed to quell investor worries about the beleaguered lender.

Fears of an imminent collapse of the San Francisco-based bank prompted a deal put together by top power brokers including U.S. Treasury Secretary Janet Yellen, Federal Reserve Chairman Jerome Powell and JPMorgan Chase CEO Jamie Dimon on Thursday.

First Republic suspended its dividend, disclosed its cash position and said its borrowing from the U.S. Federal Reserve varied from $20 billion to $109 billion between March 10 and March 15.

"While the new deposits in First Republic calmed the waters for the troubled bank, they come at current market rates, which will compress net interest income," said Art Hogan, chief market strategist at B. Riley Wealth Management.

"With an impaired earnings profile the bank may still have to explore a sale."

Shares of other U.S. mid-size banks including Western Alliance Bancorp shares and PacWest Bancorp dropped 2% and 5%, respectively.

First Republic was caught up in a widening banking crisis triggered by the collapse of two other mid-size U.S. lenders over the past week.

The rescue package came less than a day after Swiss bank Credit Suisse clinched an emergency central bank loan of up to $54 billion to shore up its liquidity.

(Reporting by Joice Alves in London and Medha Singh in Bengaluru; Editing by Amanda Coopr and Sriraj Kalluvila)