Oil softens after OPEC decision prompts big weekly rally

By Ron Bousso LONDON (Reuters) - Oil prices fell 1.5 percent to steady at around $53 a barrel on Friday after the biggest weekly rally since 2009 following OPEC's decision this week to cut crude output in order to rein in a global glut. The market focus now shifts to the implementation and impact of OPEC's first production agreement since 2008, which will be joined by non-OPEC producers, after data showed output in Russia rose in November to a post-Soviet high. Russia also agreed to cut output b