Liability: To understand BP's liability, one must recognize that the company is not a monolithic entity. Rather, it is composed of scores of different corporate entities across the globe. Each of them has its own limited liability and is run separately to preserve those liability limits. In the United States, this concept of limited liability is well established and respected unless the law overrides it or a corporate parent does not treat a subsidiary entity as separate.
In the United States, BP's operations are run by BP Holdings North America Inc. According to BP's annual report, this subsidiary has about $50 billion in long-term assets. It is a separate operation and is presumably the one that, through another subsidiary, operated the oil rig in the Gulf of Mexico.
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