A federal commission investigating the Deepwater Horizon oil spill said "identifiable mistakes" by BP PLC, Halliburton Co. and Transocean Ltd. led to last year's disaster, in findings that also conveyed broad concerns about oil-drilling safety.

In a widely anticipated report released Tuesday, the seven-member panel said government oversight of the industry would require "fundamental reform," including additional funding for drilling regulators, and that oil companies will need to "dramatically" step up safety practices.

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