Bay National Corp. announced Wednesday that it notified the Nasdaq Stock Market that it plans to voluntarily delist its common stock from the exchange. The holding company for Lutherville-based Bay National Bank has been operating under federal oversight since last year as it tries to recover from losses on bad mortgage loans. This month the company said in a filing with the Securities and Exchange Commission that the bank has been classified by federal regulators as "critically undercapitalized." That means the institution could be placed in conservatorship or receivership within a few months. The board of directors, according to the filing, has adopted a "strategic plan" to restore "higher capitalization, strong earnings and good asset quality." The company's last day of trading on the Nasdaq is expected to be June 4.