Citi, Visa Win Costco's Business

Costco Wholesale Corporation COST announced on Monday that Citigroup Inc C and Visa Inc V would be its new credit partners. The news follows an announcement last week that Costco and American Express Company AXP would end their partnership.

The news helped Citigroup to gain 0.8 percent in pre-market trading, while Visa added 2.4 percent. Rivals Capital One Financial Corp. COF and Mastercard Inc MA fell 0.5 percent and 1.1 percent, respectively.

American Express dropped 12.3 percent this year as the Costco news weighed on price. The company said that it is attempting to convert current Costco cardholders onto other American Express credit cards.