SOFIA: Bulgaria on Wednesday switched its candidate to be the next head of the United Nations, shaking up the race to succeed Ban Ki-moon when he steps down on December 31. Sofia is now throwing its weight behind European Commission Vice President Kristalina Georgieva, dumping UNESCO chief Irina Bokova after she came a lowly sixth in the latest round of informal voting in New York. “We think it will be a more successful candidacy,” Prime Minister Boyko Borisov said ahead of a government meeting. Borisov said that Bokova, 64, had been given a “final chance” in the most recent vote but was jettisoned after she “fell even further and was overtaken by several other countries and other female candidates”.