BP was responsible for a "series of failures" which led to a fatal explosion at its largest US refinery in March.
The explosion killed 15 workers and injured 170 at the plant in Texas.
An interim report into the tragedy said staff failed to follow the proper procedures. It also said poor supervision at the plant contributed to the explosion.
It concluded that managers failed to supervise the unit properly while operators were absent at crucial periods and failed to take corrective action early enough.
Staff also failed to sound the alarm to evacuate when it became clear that pressure in the unit was at unsustainable levels.
BP said it would offer “fair compensation” to the victims' families and the injured to avoid the need for litigation.
