Brent oil posted its longest run of quarterly losses in data going back more than three decades amid robust supplies and persistent concerns over demand. Oil has faced worries about a potential global economic slowdown as well as a lacklustre recovery in China. Robust crude exports from Russia and Iran have kept supplies ample, outweighing a potential pickup in summer demand and production cuts from the Organization of Petroleum Exporting Countries. The global benchmark settled below $75 ....