Highmark Inc., leading health insurance provider, took a big step into the hospital business with a deal to invest up to $475 million in the region’s second largest health network: West Penn Allegheny Health System. The partnership was unanimously approved by the boards leading both organisations. The combined resources of the two will present a greater challenge to the University of Pittsburgh Medical Center for health-care consumers in the region. For the struggling West Penn Allegheny system, the Highmark merger could not have come at a better time. West Penn Allegheny had lost another $22 million in the first quarter of this year and Bloomfield’s West Penn Hospital was facing imminent closure. The regulatory approval process could take months, but both sides are confident there won’t be any major roadblocks.