The Organization of the Petroleum Exporting Countries Secretary-General said on Sunday that the group’s exporters should not cut output to “subsidize” higher-cost shale, an energy source whose recent growth is blamed by OPEC for weakening oil markets. Abdullah al-Badri added in remarks to a conference in Bahrain that tight oil, a term he has used for shale, was “not a challenge for us” but the market should now be left to decide which source of petroleum could survive at current prices. Oil prices have sunk to near six year lows in recent months as a result of a large supply glut, due mostly to a sharp rise in U.S. shale production as well as weaker global demand. The rapid decline has left several smaller oil producing countries reeling and has forced oil companies to slash budgets. “We welcome tight oil… but this source of energy costs […]