NEW ORLEANS (AP) -- Federal regulators on Wednesday cited oil company BP PLC and two other companies -- Transocean Ltd. and Halliburton -- for alleged safety and environmental violations stemming from last year's rig explosion and massive Gulf oil spill. The companies have 60 days to appeal the citations issued by the Interior Department's Bureau of Safety and Environmental Enforcement. The bureau says the alleged regulatory violations could result in civil penalties once the appeal period has ended. These initial citations are the product of a federal government probe of the Deepwater Horizon blast, which killed 11 workers and hastened the nation's worst offshore oil spill. "To ensure the safe and environmentally responsible conduct of offshore operations, companies that violate federal regulations must be held accountable," BSEE Director Michael R. Bromwich said in a statement.