U.S. retail and marketing continuing operations generated earnings of $88.0 million in the third quarter of 2011 compared to earnings of $59.0 million in the 2010 quarter. Murphy Oil Corp.’s net income in the third quarter of 2011 totaled $406.1 million ($2.09 per diluted share), which was double the net income of $202.8 million ($1.05 per diluted share) in…