Bell National filed for protection under Chapter 11.

The San Francisco-based firm’s primary asset, Bell Savings & Loan Assn., was taken over by federal regulators last month, leaving Bell National with a preliminary, unaudited negative net worth of $23 million, the company said. Just before filing, Bell National named Nicholas E. Toussaint as its president and chief executive. Fred F. Enemark, who served temporarily as head of Bell National, resigned and was made vice president.