The candor of the announement is noteworthy.

The American Red Cross forced its president and chief executive, Mark W. Everson, to resign yesterday because he had an inappropriate relationship with a female subordinate, a spokeswoman for the disaster relief agency said.

Everson’s ouster was a blow to the Red Cross, which has faced a rapid turnover in leadership and has struggled to restore a reputation damaged by its response to Hurricane Katrina. The agency’s fifth chief in six years, Everson was at the helm of the federally chartered organization for six months.

The Red Cross board of directors asked for his resignation after learning of the relationship 10 days ago, spokeswoman Suzy C. DeFrancis said.

The New York Times interviewed Trent Stamp of Charity Navigator, seeking his accessment of the dismissal.

Trent Stamp, president of Charity Navigator, a Web site that rates the efficiency of charities based on financial statements filed with the government, said the firing was a major setback for the Red Cross. “This will affect fund-raising, organizational morale and public trust in this organization, which is already dangerously low,” he said.

He noted that the organization appeared to be turning a corner under Mr. Everson, earning generally high marks for its performance during the recent California wild fires. “I’m worried that that good will will be undone,” Mr. Stamp said.

Organizations, whether for-profit or not, rarely describe their reasons for firing an executive as bluntly as the Red Cross did. The most similar comparison is the Boeing Corporation, which forced the resignation of two chief executives because of ethical lapses, including affairs with employees.

Mr. Everson, who is 53, did not respond to a message left on his cellphone. In a statement released by the Red Cross, he said: “I am resigning my position for personal and family reasons, and deeply regret it is impossible for me to continue in a job so recently undertaken.”

Earlier this year, Trent Stamp had conducted an interview with Everson, who had, at the time set forth a clear vision for the Red Cross.