Plagued by turmoil at the top, the American Red Cross ousted its president, Mark Everson, yesterday for engaging in a “personal relationship” with one of his subordinates. He took the challenging job just six months ago.

The congressionally chartered charity, America’s foremost emergency responder, has now had five leaders in the past six years including the interim chief named to fill in for Everson.

Mr. Everson, a former corporate executive and commissioner of the Internal Revenue Service, assumed the Red Cross post on May 29 as the charity sought to restructure itself and bolster its public image following sharp criticism of its response to Hurricane Katrina.

The Red Cross said its board of governors asked for and received Mr. Everson’s resignation, effective immediately, after being notified about 10 days ago by a senior executive at the national office about Mr. Everson’s relationship with a woman on the staff. The woman’s name was not released. “The board acted quickly after learning that Mr. Everson engaged in a personal relationship with a subordinate employee,” a statement said. “It concluded that the situation reflected poor judgment on Mr. Everson’s part and diminished his ability to lead the organization in the future.”

The Red Cross board, which otherwise had been pleased with Mr. Everson’s performance, met with him yesterday before announcing his ouster.

The Red Cross also released a statement from Mr. Everson, 53, who is married and has two children.

“I am resigning for personal and family reasons, and deeply regret it is impossible for me to continue a job so recently undertaken,” he said.