Austrian European Commissioner Benita Ferrero-Waldner on Sunday dropped her bid for the post of director-general of UNESCO.
In a brief statement issued by the United Nation's culture agency, Ferrero-Waldner said she had decided to withdraw in the "superior interest of the organization and of European unity".
UNESCO will hold a fourth vote on Monday in the election. Egyptian Culture Minister Farouk Hosni won 25 votes out of 57 in the latest round on Saturday.
In Thursday's first round, Bulgarian candidate Irina Gueorguieva Bokova finished second ahead of Ferrero-Waldner and Russian and Ecuadorean candidates.
Ferrero-Waldner on Sunday appealed for the full respect of the "moral values and ideals" of UNESCO which she said were at stake in the election.
Hosni, who would be the first Arab to head the agency, sparked accusations of anti-Semitism last year when, asked about Israeli books in Egyptian libraries, he was quoted as telling a member of parliament:
"Let's burn these books; if there are any, I will burn them myself before you."
Hosni this year apologised for the comment and some prominent activists such as French Nazi hunter Serge Klarsfeld have accepted his regrets and supported him.
Other activists have accused Hosni of colluding in censorship and violation of press freedom in Egypt, and put pressure on UNESCO members not to vote for him.