Public hearings held last year to gather information about a proposed merger between health insurance giants Pittsburgh-based Highmark and Philadelphia-based Independence Blue Cross saw most of the testimony lining up against the merger. Average citizens, economists, doctors and hospital officials expressed concerns that the giant company that would be created by the proposed merger would be even more difficult to deal with and more prone to take advantage of its near-monopoly status.

The message from the months of testimony was that there was not enough price competition among health insurers in Pennsylvania and a Highmark-IBC merger would only make it worse.

Based largely on fears of what diminished competition would mean to consumers, doctors and hospitals, the merger was not approved and the companies announced they were calling off plans to merge.

Preventing the merger was appropriate, and a good thing for consumers, health care providers and employers offering health insurance. But much of the testimony at the hearings, including references to a noncompete agreement between Highmark and IBC that had expired, raised questions about the competitiveness of the health insurance market in Pennsylvania.

Now, those hearings appear to have produced another positive outcome — the state Department of Insurance is planning to investigate Blue Cross- and Blue Shield-affiliated health insurance companies in Pennsylvania to determine if any engage in anti-competitive or unfair trade practices.

The hearings over the Highmark-IBC merger raised questions to warrant an investigation. But additional information that might have helped triggered the probe is found in a federal lawsuit filed by West Penn Allegheny Health System charging that Highmark and University of Pittsburgh Medical Center (UPMC) engaged in collusion in an attempt to "destroy West Penn Allegheny."

Though it's important to remember that West Penn and UPMC are competitors in Western Pennsylvania, it also is possible that West Penn's charges have merit, and that UPMC and Highmark have used their dominant market positions to harm — or try to eliminate — competition.

The public could benefit from an investigation into the business practices of the four Blue Cross and Blue Shield affiliates in the state. In addition to any evidence of anti-competitive actions or collusion to harm competitors, the investigation should look at the billions of dollars the nonprofit insurance companies hold as reserves against future claims. Many people have argued that these reserves — estimated at $3.5 billion for Highmark — are excessive. It is often argued that instead of holding such a high level of excess profits, the companies could reduce premiums paid by individuals or companies offering health insurance to employees.

The state investigation into Highmark's business practices is timely, given the national attention being focused on health insurance affordability and availability as well as cost-saving opportunities across all those involved in health care, which represents about one-sixth of the U.S. economy.

Insurance Commissioner Joel Ario is demonstrating an appropriate response to testimony over the lack of competitiveness in the state's health insurance market. His investigation also might shed light on how Highmark and UPMC use their market-dominating positions to stifle competition and keep costs high.

Ario's investigation, which is expected to be completed in early 2010, is welcome. The public will be well served by a probe into the business practices of giant nonprofit companies such as Highmark and the impact of those practices on consumers and the cost of health care in Pennsylvania.