London- Scotland Yard chief Ian Blair resigned from his post Thursday following a series of allegations ranging from corruption to racism and the shooting of a Brazilian man mistaken for a terrorist.

Blair, 55, Britain's most senior policeman, said he had taken the "personal decision" to step down as commissioner of the Metropolitan Police long before his current contract ends in January 2010.

Blair has been severely criticized in connection with the killing by police of Brazilian Jean Charles de Menezes who was mistaken for a terrorist during a police hunt in July 2005.

The police chief was also embroiled in a sensitive conflict with top Asian officers in the London police force who accused him of "racial discrimination." (dpa)