http://www.bbc.co.uk/news/business-14767446
2 September 2011 Last updated at 15:13 GMT BP sued by Halliburton over Gulf oil disaster
About five million barrels of oil spilled into the Gulf of Mexico
US energy services giant Halliburton is suing BP for defamation and negligent misrepresentation over the disastrous 2010 oil spill in the Gulf of Mexico.
Halliburton claims BP gave inaccurate information to the US company before it did work lining the well with cement.
An official inquiry found that faulty cementing contributed to the disaster, which killed 11 oil rig workers.
BP said it was aware of the lawsuit and, should it come to court, they would "vigorously contest the claims".
The amount of damages Halliburton is seeking has not been disclosed.
'Diverting attention'
Halliburton said in a statement that it has "filed claims against BP in Texas state court for negligent misrepresentation, business disparagement and defamation" related to the Deepwater Horizon disaster.
"Halliburton has learned that BP provided Halliburton inaccurate information about the actual location of hydrocarbon zones in the well. "The actual location of the hydrocarbon zones is critical information required prior to performing cementing services and is necessary to achieve desired cement placement," Halliburton said.
"Halliburton remains confident that all the work it performed... was completed in accordance with BP's specifications for its well construction plan and instructions, and that Halliburton is fully indemnified under the contract," the company said.
But BP said: "We believe this lawsuit is the latest attempt by Halliburton to divert attention from its role in the Deepwater Horizon tragedy and its failure to meet its responsibilities, and to deflect all blame to BP.
"Investigations published so far have concluded that multiple parties contributed to the incident, including Halliburton.
"We have accepted responsibility for our role in the disaster, and are paying costs and compensation. In contrast Halliburton has refused to take any responsibility or accountability at all."
Some 4.9 million barrels of oil had gushed out of the runaway underwater well before the leak was capped, causing severe environmental damage in the Gulf of Mexico.