Oil prices fall to their lowest level since AprilOil prices slid to their lowest levels since April yesterday amid signs that production cartel Opec was planning to keep supply levels steady. September 10th 2008, 2:21 am 2 min read Facebook An icon of a facebook f logo. LinkedIn An icon of the LinkedIn logo. Twitter An icon of the Twitter logo. Oil prices slid to their lowest levels since April yesterday amid signs that production cartel Opec was planning to keep supply levels steady.