FedEx says customers who left UPS aren’t going back. FedEx gained hundreds of thousands of parcels per day worth of business after United Postal Service was roiled by labor negotiations over the summer. UPS and the Teamsters reached a deal in July, but FedEx Chief Customer Officer Brie Carere says on a call with analysts Thursday that FedEx held on to the vast majority of the business it gained. Notably, UPS has said the exact opposite: CEO Carol Tomé said after the company’s fourth-quarter earnings that it had won back nearly 60% of volume lost during labor talks. FedEx shares gain 13%, to $299.75, after hours.