NEW YORK - Plagued by turmoil at the top, the American Red Cross ousted its president, Mark Everson, on Tuesday for engaging in a "personal relationship" with one of his subordinates. He took the challenging job only 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.

Everson, a former corporate executive and IRS commissioner, assumed the Red Cross post May 29 as the charity sought to restructure itself and bolster its image following criticism of its response to Hurricane Katrina.

The Red Cross said its board of governors asked for and received Everson's resignation, effective immediately, after being notified about 10 days ago by a senior executive at the national office about 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 Everson's performance, met with him Tuesday before announcing his ouster.

The Red Cross also released a statement from 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. "I leave with extraordinary admiration for the American Red Cross."

Everson's departure continues a trend of rapid turnover atop the Red Cross. The two women who preceded him as president both resigned over friction with the board of governors -- Bernadette Healy after the Sept. 11 attacks and Marsha Evans in 2005, after Katrina. An interim president, Jack McGuire, served between Evans' departure and Everson's appointment.

The Red Cross board appointed Mary Elcano, its general counsel for the past five years, as interim president. Elcano's experience includes a stint as executive vice president of human resources with the U.S. Postal Service.