United States v. Philadelphia National Bank

Philadelphia National Bank (PNB) (defendant) and Girard Trust Corn Exchange Bank (defendant), the second- and third-largest commercial banks in the Philadelphia area, planned to merge into what would become the area's largest bank, holding over 30 percent of the relevant market and increasing market concentration by more than 33 percent. The government sued to block the merger under § 7 of the Clayton Act; PNB argued pro-competitive benefits justified the merger and that the relevant geographic market should be expanded to include large New York banks, and the district court ruled for PNB, prompting a government appeal.