RIO DE JANEIRO, June 11 (Reuters) - Brazil's state-run oil company Petroleo Brasileiro SA said on Thursday that procedural failures contributed to a deadly explosion on the Cidade de Sao Mateus production rig in February that left nine dead and 26 injured.
The statement was part of a report on the accident generated by the company, which it said it has already delivered to the oil and gas regulator ANP.
The floating, production, offloading and storage vessel Sao Mateus was operated by the Norwegian firm BW Offshore Ltd. and deployed in the Camarupim oil and gas fields off the coast of Espirito Santo, in Brazil's southeast.
Petrobras said the failure to pump fluids, install the correct equipment in pipelines and the failure to observe safety measures were the principal causes of the explosion. (Reporting by Marta Nogueira; Writing by Reese Ewing; Editing by Bernard Orr)