WASHINGTON - THE head of the World Bank's anti-corruption unit, Ms Suzanne Rich Folsom, resigned on Wednesday to rejoin the private sector, a Bank spokesman said.

Ms Folsom, a United States ethics lawyer, had been dogged by controversy since her appointment in 2005 by former Bank President Paul Wolfowitz, who resigned in June amid an ethics scandal involving his companion.

World Bank spokesman Marwan Muasher emphasised that Ms Folsom had not been forced from her position.

"I want to make it clear that she was not fired, she was not forced out. She has a very good offer from the private sector and she chose to take it", Mr Muasher said.

"When she approached the Bank (with her resignation), the president offered her another job within the Bank but she declined", he said, adding, "There was no attempt to force her out in any way or shape".

Mr Muasher named Mr John Zutt, a Dutch national who has worked at the Bank as a senior adviser and a lawyer with degrees from Harvard and Oxford, to replace Ms Folsom temporarily at the Department of Institutional Integrity until a permanent director was appointed.

A panel led by former United States Federal Reserve Chairman Paul Volcker last year recommended that the World Bank examine the role of Ms Folsom's anti-corruption unit following concerns about its investigative practices.

In an interview at the time, Mr Volcker said it was not the panel's mandate to judge individuals like Ms Folsom but he insisted she got high marks for professionalism.

"There is no doubt there are a lot of accusations made about whether decisions have been politically involved", Mr Volcker said, adding that the panel did not find systematic evidence that was the case. -- REUTERS