Social Democrat leader Borut Pahor smiles as his colleagues congratulate him in parliament after being confirmed as the new prime minister in Ljubljana November 7, 2008. [Photo: REUTERS]

Borut Pahor of Slovenia's leftist Social Democrat party took office Friday as the country's sixth prime minister, soon after parliament endorsed his candidacy with 59 votes for and 24 against, the official Slovenian news agency STA reported.

In a short address to parliament, Pahor said he would "respect the constitution, act by my conscience and do everything in my power to work for the good of Slovenia."

Pahor thanked the lawmakers for their endorsement, while adding that he did not see their support as a "blank cheque."

Pahor, 45, was formally nominated as the prime minister designate by President Danillo Turk on Monday.

On Thursday, Pahor initialed a coalition agreement with the Zares, Liberal Democrats and Pensioners' parties. The four-party coalition has 50 seats in parliament, more than the absolute majority of 46 seats required to elect a new prime minister in the 90-member parliament.

Six of the seven parliamentary parties had pledged their support to him. Only the leading opposition Slovenian Democrats said they would not back Pahor.

He now has 15 days to form a cabinet and put it to a vote in parliament.

Pahor's Social Democrats won 29 seats in the Sept. 21 general election, narrowly defeating outgoing Prime Minister Janez Jansa's center-right Slovenian Democrats.