Best Buy Co. BBY +0.59% , for example, installed NFC-enabled scanners in many of its stores but switched them off in 2011 because the cost of supporting the platform was too high, the company spokesman said.

The retailer has no plans to change course following Apple's announcement.

In part, mobile payments have suffered from a classic chicken-and-egg situation. Smaller merchants in particular were reluctant to install the systems—which can cost $300 to $500 per device—because few consumers were using them. Moreover, merchant fees for mobile-payment systems can be higher than for plastic cards, particularly for debit cards, Mr. Crone said.

Best Buy and Wal-Mart are instead backing a retailer-owned mobile technology group called Merchant Customer Exchange, which also counts Target Corp. among its members.

MCX's payment service requires only a software download and can be used on existing iPhones and Android devices, whereas Apple's is only for the latest generation handset.

The group announced the launch of a mobile wallet application called CurrentC, which it said will run as a pilot in certain cities before being rolled out nationally in 2015.

CurrentC said it will link with customers' checking accounts, retailer gift cards and select merchant-branded debit and credit accounts but doesn't currently sync with traditional credit cards. Unlike Apple Pay, CurrentC doesn't use NFC technology. Instead a retailer scans a digital QR code on its smartphone app.