Pittsburgh-based health insurer Highmark's earnings have declined over the past 12 months and are unlikely to improve meaningfully over the intermediate term (12-24 months) because of market-specific challenges (such as the slightly unfavorable regulatory environment) and broader macroeconomic conditions. As a result, we are revising our outlook on Highmark to negative from stable. We are affirming our 'A' counterparty credit and financial strength ratings on the company. NEW YORK (Standard&Poor's) Dec. 2, 2009--Standard&Poor's Ratings Services today said it revised its outlook on Highmark Inc. (which does business as Highmark BCBS&Highmark Blue Shield) to negative from stable. At the same time, we affirmed our 'A' counterparty credit and financial strength ratings on the company. "Our