UNITED NATIONS, Feb 21: Ruud Lubbers, the United Nations High Commissioner for Refugees, has stepped down from his post amid the persistent controversy over allegations of sexual impropriety - a move that Secretary General Kofi Annan welcomed as serving the wider interest of the UN refugee agency.

Just two days after insisting he would stay in his Geneva post, Mr Lubbers released a bitter resignation letter to the UN secretary-general in which he alluded to feeling let down by an apparent change of mind by Mr Annan regarding the case.

The allegations, made by a female employee of the refugee agency in Geneva, were investigated by the United Nations last summer, but Mr Annan decided at the time there was insufficient proof for action against the former Dutch premier.

In a statement issued on Sunday by his spokesman, Annan thanked Mr Lubbers for his "commitment" to refugees, but said "it is in the best interest of UNHCR, its staff and the refugees it serves that the page be turned and a new chapter be started."

When allegations against Mr Lubbers surfaced last year, he vigorously denied them - a position he has maintained throughout. Speaking to reporters in New York on Friday following a meeting with the secretary-general, Mr Lubbers dismissed the accusations as a campaign of slander.

The charges came from a UNHCR staffer who said the 65-year old former Dutch prime minister sexually harassed her during a meeting in December 2003. Referring to that encounter in a statement released after the charges were formally brought the following May, Mr Lubbers asserted "there was no improper behaviour on my part."