The nation’s four largest wireless carriers have stopped or nearly stopped selling access to subscribers’ real-time location data to third-party data brokers, amid an ongoing Federal Communications Commission probe into their data-sharing practices.

AT&T Inc., Sprint Corp., T-Mobile US Inc., and Verizon Communications Inc. said they’ve moved to stop selling their customers’ location data to location aggregation companies, in letters to Democratic FCC Commissioner Jessica Rosenworcel. AT&T, T-Mobile, and Verizon said they’ve stopped contracting with location aggregators. Sprint said it’s...