Banco Santander, Spain's largest commercial bank, announced in July 2004 the acquisition of Abbey National Bank, the fifth largest U.K. commercial bank. This transaction was the largest ever cross-border acquisition in European banking and would result in the 10th-largest bank in the world. Discusses the main sources of value creation from international expansion and acquisitions in the commercial banking industry. Also, highlights the barriers to integration within the single market of the European Union in a regulated service industry such as commercial banking.