Stamford-based Synchrony to end card partnership with Gap FacebookTwitterEmailLinkedInRedditPinterest Photo: Patrick T. Fallon / Bloomberg STAMFORD — Synchrony, the country’s largest private-label credit card provider, will end next year its two-decade partnership with Gap Inc., after the companies were unable to agree on a program renewal. Stamford-based Synchrony has been issuing cards for Gap for about 22 years, with the latter comprising one of Synchrony’s five-largest retail card partners. Their program includes about 11 million open card accounts, with balances totaling approximately $3.8 billion at the end of March. The portfolio represents about 5 percent of Synchrony’s loan receivables. Synchrony is headquartered at 777 Long Ridge Road in Stamford, Conn.