BP is expected to accept some of the blame for the Gulf of Mexico oil spill but say that it was not guilty of any gross negligence that could lead to a criminal enquiry in a report on the disaster due later today.The oil giant is expected to shift some of the blame to oil services group Halliburton and rig operator Transocean. TheDeepwater Horizon well exploded on April 20, killing 11 workers and leading to a huge oil spill.Deepwater Horizon was owned by Transocean, with Halliburton carrying out the cementing work.The report is the result of an investigation by BP's head of safety and operations Mark Bly.BP is also facing investigations in the US, where the oil spill has provoked widespread public anger. The oil spill has wiped billions of the market value of BP and resulted in the resignation of its chief executive.The oil spill also prompted calls from environmentalists for limits or outright bans on deepwater drilling.