ERIE — Erie’s Saint Vincent Health System is affiliating with Highmark as the insurer continues to move into the health-delivery business with its chief rival, the University of Pittsburgh Medical Center.

The move was announced Tuesday. Saint Vincent says its board voted unanimously to pursue a strategic affiliation with Highmark.

UPMC, which has its own health insurance plan, has been affiliated with Erie’s other major hospital, the former Hamot Medical Center, since February 2011.

Highmark’s efforts to take over the Pittsburgh-based West Penn Allegheny Health System have hit a snag after that hospital network backed out of a $475 million deal earlier this year, though efforts to save that deal are continuing.