The Pittsburgh-based insurer, in a dispute with the area's largest hospital system, wants to occupy what it calls the "provider space." Emily Berry, American Medical News, December 26, 2011 Faced with a future where its home region's largest health system could be outside of its network, Pittsburgh-based Highmark plans to buy and affiliate with more hospitals and physician practices. Highmark's June announcement that it would purchase West Penn Allegheny Health System established its first large-scale foray in the clinical side of the health care business. It also contributed to the deterioration of contract negotiations with the University of Pittsburgh Medical Center ... Highmark