State news agency, SANA said Otri's appointment came after President Bashar accepted the resignation of the cabinet of Prime Minister Muhammed Mustafa Miro.
"Prime Minister Mohammed Mustafa Miro submitted the resignation of his government to President Assad who accepted it and charged Mohammed Naji al-Otri with forming a new government," the news agency reported.
President al-Assad asked the outgoing government, formed in December 2001 to "quickly complete the outstanding tasks on its agenda until a new government is formed," SANA said.
The president had hinted at the change of guard last month, stating that pushing through reforms would be the main task of the new cabinet he planned to form.
Wednesday's change of prime minister is the first since al-Assad took office in 2000, succeeding his late father, Hafiz al-Assad.
On succession, he had reshuffled the cabinet, changing key portfolios of finance and economy, but left the prime minister and other key political figures in place.
Economy Minister Ghassan Rifai had earlier said he wanted to accelerate the pace of economic reform, but added that Syria did not intend to plunge into privatization as it reformed the state-dominant economy.
"We need to be faster. We need to be more courageous. We need to cut down on the paperwork," Rifai said.