the news sent shares of CoreCard Corp. and Green Dot Corp. -- two of Apple’s existing partners -- down more than 10% apiece on Wednesday. Goldman Sachs Group Inc., another key partner, slipped as much as 1.2%.

The push would turn the company into a bigger force in financial services, building on a lineup that already includes an Apple-branded credit card, peer-to-peer payments, the Wallet app and a mechanism for merchants to accept credit cards from an iPhone.