Albert Manifold has been removed as BP chair with immediate effect
BP has sacked its chairman less than a year after he took on the role.
The surprise departure follows what the oil giant described as "serious concerns" over governance, oversight and conduct.
Albert Manifold has been removed as BP chair with immediate effect, the company announced on Tuesday.
Amanda Blanc, BP's senior independent director, said: "Albert has helped bring a welcome focus and pace to BP's transformation.
"However, the board has been surprised and disappointed to learn of governance oversight and conduct issues it deems unacceptable and has taken decisive action."
Board member Ian Tyler has been appointed interim chair while the company searches for a permanent replacement.
Mr Manifold has criticised a "false narrative" after he was removed as BP chairman on Tuesday.
In response, Mr Manifold said: "I was removed without warning and without explanation.
"During my time as chairman I worked to drive genuine change at BP – cutting costs, challenging excess, and holding the organisation to higher standards.
"The board’s statement this morning acknowledged the focus and pace I brought.
"I dispute entirely the characterisation of my conduct and I will not allow a false narrative to go unchallenged."
He took over from Helge Lund, whose six-year tenure was marked by growing pressure from investors.
The outgoing chairman had already faced shareholder resistance at BP's annual general meeting last month.
Although he secured re-election, more than 18 per cent of investors voted against him after proxy adviser Glass Lewis raised governance concerns and recommended shareholders oppose his appointment.
BP shares fell four per cent on Tuesday afternoon following news of his departure.