Oil prices edge up amid Brexit concerns, supply risks

Oil prices were slightly higher after falling earlier in Asian trading on Wednesday amid the wider market turmoil set off by mounting concerns over the economic impact of Britain's vote to leave the European Union. The contract fell 5 percent to end at $46.60 on Tuesday as U.S. investors digested news of an OPEC increase in production after the July 4 holiday on Monday closed trading. Oil prices are up almost 80 percent from 12-year lows of around $27 for Brent and $26 for U.S. crude in the firs