Brent and West Texas Intermediate (WTI) crudes fell to their lowest level in more than four years after OPEC failed to cut its output in response to a glut. Both grades capped the biggest monthly drops since 2008. OPEC will maintain its collective output target at 30 million barrels a day, Saudi Arabian Oil Minister Ali al-Naimi said after discussions in Vienna yesterday. The group’s policy will ensure a crash in the U.S.