BP has admitted that a review into the fatal 2005 blast at its Texas City refinery found "shortcomings" in the performance of some of its managers.
BP has said it is improving safety standards
Yet the firm added that there was "no evidence that anyone acted in bad faith or violated BP's code of conduct".
It made the comments after a report in the Financial Times alleged that BP's internal report recommended that four bosses at the firm should be fired.
BP said that, as a matter of policy, it did not comment on personnel matters.
The 2005 explosion at BP's Texas City refinery in the US killed 15 people and injured 180.
Last month, a separate independent report into the blast, led by former US Secretary of State James Baker, found that while BP emphasised personal safety, it was weak on process safety.
The Baker report said the problem existed at all five of BP's US refineries.
BP said at the time that it had already taken significant steps to improve safety.