WASHINGTON — The Justice Department said Wednesday that it had ended an investigation into possible coordination among AT&T, Verizon and a standards-setting organization to make it more difficult for people to switch wireless carriers. The agency said the groups had agreed to change their practices, reducing competition concerns.
In its investigation, which began two years ago, the Justice Department looked into whether the two companies and a trade association, known as G.S.M.A., that sets mobile technical standards had worked together to hinder a technology called eSIM. The technology lets people remotely switch wireless providers without having to insert a new SIM card into a device.
The Justice Department dropped its investigation after the parties agreed to change how they determine standards for eSIM, the agency’s head of antitrust, Makan Delrahim, said in a letter to the trade group. The change will allow consumers to use the technology to switch carriers, the agency said.
“We applaud G.S.M.A.’s efforts to ensure that its new process provides for an adequate balance of interests,” Mr. Delrahim wrote.
The standards group said the investigation had turned up no wrongdoing. The group said it remained “committed to a consensus-driven approach that protects all groups involved in the development of industry specifications.”
AT&T referred to the statement from the standards group. Verizon declined to comment.
The decision is an anticlimactic end to an investigation that included demands for millions of pages of internal documents from the companies. The investigation came to light during the Justice Department’s lawsuit to block AT&T’s merger with Time Warner, a case Mr. Delrahim’s antitrust division lost.
At the heart of the investigation was whether the nation’s biggest wireless carriers, working with the standards body, used the eSIM technology to unfairly maintain their dominance. A device maker and one rival wireless carrier filed formal complaints to the Justice Department that the organizations had hurt competition and consumers and hindered innovation in the mobile industry.
AT&T and Verizon together control about 70 percent of all wireless subscriptions in the United States. A technology that made it easy to switch carriers could lead to more turnover and fewer subscribers for them.
The eSIM technology has become more common in mobile devices, replacing the fingernail-size SIM cards, which freed up space in the phone for other features.