President Ilham Aliyev of Azerbaijan has appointed a close ally as the new Prime Minister following the sudden resignation of his predecessor.

“The president has appointed his economic adviser Ali Asadov as new prime minister,” parliament speaker Oktay Asadov told legislators on Tuesday.

“Prime Minister Novruz Mammadov has tendered his resignation which has been accepted by the president,” he added.

Legislators approved the nomination of Asadov in a 105 to 0 vote.

The reason for Mammadov’s resignation has not been given.

Observers describe Asadov, a 63-year-old presidential aide on economic issues, as Aliyev’s long-time ally.

Energy-rich Azerbaijan has been hit hard by a global slump in oil prices and the new appointment may be motivated by Aliyev’s desire to kick-start the stagnant economy, according to analysts.

Mammadov was appointed Prime Minister in April last year after having served as Aliyev’s foreign policy adviser and deputy head of presidential staff.

With most powers concentrated in the hands of the president under the constitution, the prime-ministerial post is seen as largely a nominal role traditionally held by Aliyev’s close lieutenants.

The president has ruled the Caspian state with an iron fist since he was first elected in 2003, after the death of his father, Azerbaijan’s Soviet-era Communist leader and former KGB general Heydar Aliyev.

Under the Aliyev dynasty, Baku has faced strong international criticism for silencing dissent and opposition media.