The president and chief executive of Nara Bancorp Inc. resigned unexpectedly, the second management shake-up at the Korean-American bank in the past year.

The Los Angeles-based parent company of Nara Bank announced on Thursday that Ho Yang submitted his resignation the day before, effective March 15. No reason was given for the management change.

The company has not named a replacement for Yang, who was appointed in March 2005 after the ouster of Benjamin Hong, the bank’s former chief executive.

Hong, who earned a reputation as the “godfather” of Korean-American banking, was named president and chief executive earlier this month of Saehan Bancorp.

Hong was ousted in a power struggle with Chong-Moon Lee, Nara’s current chairman, who controls 3 percent of the bank’s shares.

Shares of Nara fell 6.3 percent to settle at $15.90 on Thursday.