NY -- Standard&Poor's CreditWire 7/6/98 -- Standard&Poor's today affirmed its single-'A' corporate credit rating on LOOP LLC and its 'A-1' commercial paper rating on LOCAP Inc. Approximately $430 million in debt securities are affected. The outlook is stable. The rating affirmations follow changes in ownership at both companies, which in sum are expected to have a neutral impact on credit quality. Ratings on LOOP and LOCAP are supported by throughput and deficiency (T&D) agreements (several, not joint) with its owners, all of which are large integrated oil companies. One pair of owners has merged its downstream assets to form a new company, Marathon Ashland Petroleum LLC (MAP), while another pair of owners executed a similar merger