Latvian President Vaira Vike-Freiberga said her candidacy to become the UN chief had no chance of succeeding because she is a woman in an interview published on Sunday.
Vike-Freiberga is one of six candidates to have pulled out of the running to become Kofi Annan's successor as United Nations secretary-general. South Korean Foreign Minister Ban Ki-Moon, the only candidate left, is set to be formally endorsed as the new UN chief on Monday.
The Latvian president, who led her country into the European Union and NATO, said that she felt there was an old boys network operating at the UN.
She insisted it was high time for a woman to fill the world's top diplomatic post.
"I hope my candidacy will make it easier," she said.
"But whether it will take another 60 years or another 600, I have no way of knowing."
Last Monday, Ban, 62, won a decisive fourth straw poll in the Security Council after securing crucial backing from its five veto-wielding permanent members: Britain, China, France, Russia and the United States.
Under the UN Charter, the secretary general is elected by the 192-member General Assembly on the recommendation of the Security Council.