The head of Greece's Supreme Court, Vassiliki Thanou, was named Thursday as the country's caretaker prime minister ahead of early elections, the president's office said.
Thanou, who at 65 will be the first woman to assume the post, will take her oath of office later Thursday and her administration will be sworn in on Friday, it said.
The date for Greece's general election - the fifth in six years - is to be officially announced by President Prokopis Pavlopoulos by the end of the week, but it is likely to be scheduled for September 20.
Outgoing Prime Minister Alexis Tsipras on Wednesday ruled out forming a national unity government should he fail to win a outright majority in the snap elections triggered after he resigned last week.
Tsipras, who called for the fresh vote last week after suffering a major rebellion in his hard-left Syriza party over Greece's huge new international bailout, dismissed suggestions he could work with the conservative opposition New Democracy, the Pasok socialists or the centre-right Potami if the poll results were inconclusive.