Shares of several banks in the U.S. have plunged following the sale of First Republic Bank to JP Morgan by federal authorities.

PacWest Bancorp’s shares plunge 28 per cent. Shares in Western Alliance dropped 15 per cent.

The rescue of First Republic this week has failed to arrest a sell-off in regional bank shares.

Trading in PacWest Bancorp, which according to the Financial Times, is seen as one of the weakest of the midsized regional banks, was briefly halted for volatility and closed down 27.8 per cent.

The fall marked PacWest’s worst daily decline since March 10, when Silicon Valley Bank’s collapse heaped pressure on the entire sector.

Other regional banks like the Western Alliance fell 15.1 per cent.

In an emergency government-led intervention, JPMorgan acquired First Republic after unsuccessful private rescue efforts failed to close a hole in the ailing lender’s balance sheet.

The development came a few weeks after First Republic disclosed that during a panic last month, customers withdrew more than $100 billion from the accounts they had opened. This disclosure increased worries that the First Republic would not be able to exist independently.