PITTSBURGH—Highmark Inc. has dropped its federal false advertising lawsuit against the University of Pittsburgh Medical Center, keeping part of its promise to end litigation now that the region's largest health insurer and biggest hospital network have agreed on a subscriber contract through 2014.

Highmark sued last year after UPMC ran ads contending Highmark patients would lose "in network" access to UPMC's doctors and hospitals once the contract expired in July 2012. The parties have since negotiated an extension and part of the deal called for Highmark to drop various lawsuits against UPMC.

Highmark has said it intends to drop an antitrust suit against UPMC, too. But a competing hospital network, West Penn Allegheny, has refused to go along with that.

State regulators are weighing Highmark's proposed $475 million takeover of West Penn, but have yet to approve it.