Sprint has ended talks to acquire T-Mobile, a person with knowledge of the matter said, as regulatory concerns outweighed the potential benefits of a deal. The third-largest U.S. wireless company plans to name a new chief executive as soon as tomorrow to replace Dan Hesse, who has led the company since 2007, said the person, who asked not to be identified because the information is private. T-Mobile, approached about a stake purchase by Iliad last week, was willing to move forward on a deal with Sprint if it agreed to sticking points including financing disagreements, people familiar with the talks said. While both companies viewed approval for a deal as a long shot, given the current administration’s stated goal of having four competitive wireless companies in the U.S., Sprint ultimately decided the regulatory environment was prohibitive, one person said.