WASHINGTON – At the request of the White House, General Services Administration chief Lurita Alexis Doan resigned Tuesday night as head of the government’s premier contracting agency, ending a tumultuous tenure in which she was accused of trying to award work to a friend and misusing her authority for political ends.

Doan’s resignation came almost a year after Rep. Henry Waxman, D-Calif., chairman of the House Oversight and Government Reform Committee, said he believed Doan could no longer be effective because of the allegations about her leadership.

Waxman’s committee began investigating Doan after stories in the Washington Post showed that she had approved a $20,000, no-bid arrangement last July with a business run by a friend and had tried to reduce the budget of the agency’s inspector general.

The committee investigation turned up evidence that Doan might have violated the Hatch Act in January 2007 by asking political appointees how they could “help our candidates” at an agency briefing conducted by a White House official, according to several of the appointees present for the briefing.

After a more extensive probe, the Office of Special Counsel concluded that those remarks violated the act, which generally prohibits employees of federal agencies from using their positions for political purposes.

In a letter in June, Special Counsel Scott Bloch urged President Bush to discipline Doan “to the fullest extent,” which would include removing her from office. In the ensuing 10 months, the White House said it was considering Bloch’s recommendation but made no further comment.