Hedge fund managers have started to turn more bearish on oil as concerns about a slowing global economy and an over-extended price rally outweigh fears about sanctions and supply disruptions. Hedge funds and other money managers were net sellers of 25 million barrels of futures and options in the six major contracts linked to petroleum prices in the week to May 7. Portfolio managers have now sold a total of 42 million barrels in the last two weeks, after buying 609 million over the previous 15 weeks since Jan. 8, according to position records published by regulators and exchanges.