Amid signs that Pennsylvania's insurance commissioner is laying out a course for Independence Blue Cross and Highmark Inc. to follow as they pursue their proposed and controversial merger, members of the boards of the two insurers are meeting. Even though by law an official decision cannot be rendered until next week, the Insurance Department has let the insurers know privately that it will not approve the merger unless the new company agrees to make an important change in how it markets health insurance in Pennsylvania, among other conditions. The marketing change has to do with how the new company, which would become the largest health insurer in the state and one of the largest in the nation, would use the popular "Blue" trademark.