Nigerian President Goodluck Jonathan has replaced the head of the powerful state oil company, his spokesman said Saturday, dismissing Andrew Yakubu after just two years on the job.
No reason was given for Yakubu's departure in favour of Joseph Thlama Dawha, but changes at the much-criticised Nigerian National Petroleum Company (NNPC) have become routine.
The move was announced in a release from Jonathan's spokesman Reuben Abati, which also listed other changes at the top of the company.
The NNPC is regarded as one of the world's most opaque and corrupt publicly-controlled oil firms and has been linked to the massive theft of vast crude revenues.
Critics say Yakubu did little to clean up the tarnished NNPC since his appointment in 2012.
Former central bank chief Sanusi Lamido Sanusi was ousted this year after he accused the NNPC of misappropriating more than 20 billion dollars over 2012 and 2013, a charge Yakubu denied.
Dawha previously held a senior post within the company and is not widely known as a reformer.
He is a native of Borno state, the area hit hardest by Boko Haram's five-year Islamist uprising.
Prominent appointments in Nigeria are often made with an eye on politics and Borno residents have become Jonathan's harshest critics amid the escalating Boko Haram violence.
Analysts say Jonathan will need some support from Borno and surrounding regions in the north if he runs for reelection next year.
Nigeria is Africa's largest oil producer, churning out roughly two billion barrels of crude per day.
Ordinary people have largely not benefited from the nation's oil wealth, with much of the revenue lost to graft.