European Union antitrust regulators opened a probe of fees set by Visa Europe, the regional franchise of the world's biggest credit-card network. Three months ago, the same commission ruled MasterCard Inc.'s similar fee is illegal.
Visa debuted on the New York Stock Exchange under the ticker symbol "V." Its historic initial public offering raised $17.86 billion. Visa's IPO is the largest domestic initial public offering in U.S. history and the third largest initial public offering worldwide.