Pennsylvania hospital West Penn Allegheny has stood up to rival University of Pittsburgh Medical Centre (UPMC)’s attempt to stop an antitrust lawsuit between the two companies, arguing that the case should continue regardless of whether West Penn eventually merges with UPMC business partner Highmark.

The US Department of Justice’s antitrust division (DoJ) yesterday closed its investigation of the merger between Highmark and West Penn Allegheny Health System (WPAHS), ruling that the tie-up could in fact bolster competition in western Pennsylvania's health-care market.

The US Department of Justice’s antitrust division (DoJ) is investigating the US$475 million merger between Highmark and West Penn Allegheny Health System over concerns the deal would reduce competition in the health-care sector.