Kazakhstan’s central bank chief Grigory Marchenko has ended his bid to head the International Monetary Fund.
He said it was “obvious” that French Finance Minister Christine Lagarde would get the job.
Ms Lagarde is in Portugal as part of a tour to drum up support, while her main rival, Mexico’s Central Bank Governor Agustin Carstens, is in India.
A new candidate, Stanley Fischer, governor of the Bank of Israel, Stanley Fischer, has joined the race.
Correspondents say his bid presents a serious challenge to the Ms Lagarde, although at 67, he is two years older than the current age limit for IMF leaders to take up the post.
“A unique, unplanned and possibly and once-in-a-lifetime opportunity has arisen to run for the head of the International Monetary Fund, which after consideration, I decided I wanted to pursue,” he said.
In the event of a deadlock between the front-runners, Mr Fischer might be seen as a compromise candidate, correspondents say.