Kazakhstan is emerging as a major source of non-Opec oil and international majors Chevron, Eni SpA and Shell have billions of dollars invested in energy projects there.

   

The state has been seeking a bigger role in the oil sector and investors will watch closely to see if the new prime minister continues this trend.

   

It was unclear why Akhmetov had resigned. Nazarbayev keeps a tight rein on ministers and often reshuffles senior officials to balance the clans around him.