MADRID (Standard&Poor's) Feb. 21, 2008--Standard&Poor's Ratings Services said today that it has lowered its long-term corporate credit rating on Spanish utility Gas Natural SDG, S.A. to 'A' from 'A+' following a review of the group's 2008-2012 strategic plan. At the same time, the 'A-1' short-term corporate credit rating was affirmed. The outlook is stable. "The downgrade reflects our view that Gas Natural's strategic plan is not compatible with an 'A+' rating, due to an expected weakening in the group's business and financial profile and credit protection measures," said Standard&Poor's credit analyst Ana Nogales. We also expect a gradual increase in the business risk of the group, with an expected reduction of the domestic regulated