Pemex provides a third of all Mexican government revenue – but is vulnerable to fraud and waste. Reuters identified $11.7 billion in Pemex contracts flagged as problematic by government auditors. But records show that authorities rarely act on those warnings. REUTERS/Oscar Martinez Mexican authorities have disregarded auditors’ warnings on billions of dollars of deals granted by the state oil giant, a Reuters examination shows. Among the businessmen who benefited: an alleged associate of the Zetas cartel. MEXICO CITY – The state-owned petroleum giant Pemex paid $9 million in 2011 to have an oil rig towed halfway round the world, from the United Arab Emirates to the Gulf of Mexico. When government auditors looked at the contract, they turned up some problems. The rig had the wrong equipment for the assignment, according to a report by Mexican congressional auditors. […]