Wells Fargo & Co., the U.S. bank with the most branches, is testing microchip-embedded credit cards with frequent travelers to address complaints of customers who have trouble using their cards abroad, Bloomberg reported. The pilot program to be announced today marks the first effort by a major U.S. bank to deploy Visa Inc. credit cards with so-called EMV-chip technology, which has become a standard in Europe and much of the rest of the world. Wells Fargo is preparing to notify 15,000 customers it identified as frequent travelers, including college students and clients of its private bank, that they’ve been invited to participate in the pilot program. The cardholders will receive the EMV cards in the middle of the year.