UPMC wants all the world to see the weeks-old agreement between Highmark and West Penn Allegheny Health System, UPMC argued Wednesday in filings in a lawsuit between the region's two big hospital networks. West Penn is fighting against disclosure of the affiliation agreement it has with Highmark, saying it is "laced with highly sensitive, confidential information" on the health system's compliance with regulations, salaries, legal battles and more. The dispute over whether to make public a private document with implications for the region's economy is the latest twist in West Penn's lawsuit. Contending that the region's big medical provider and big insurer conspired to stifle competition, it had been viewed as struggling against West Penn's legal Hail Mary pass. Now it may have been intercepted by UPMC's aggressive defense.