Updated: May 28, 4 p.m. MST

The U.S. Surface Transportation Board announced Wednesday that it had unanimously voted to accept Union Pacific’s application to acquire Norfolk Southern, although it said it still needed more information before it could fully consider the proposal.

The STB rejected UP and NS’s initial merger application in January, stating that it was “incomplete.” The board gave the railroads until April 30 to submit a revised application, which they did.

In the weeks since, Class I rivals including BNSF, CPKC and Canadian National have all railed against the proposal, saying a merger to create a 50,000-mile rail system in 43 states would be bad for competition. Opponents like BNSF urged the STB to again reject the application, alleging that UP had simply offered “cosmetic changes” to the original application.

But the STB disagreed and concluded that UP and NS had, for the most part, provided the federal regulator with the information it needed to evaluate the proposal, with a few additional pieces still required. Among the STB’s requests: more detail about enhanced competition, service assurance plans, car supplies and downstream merger impacts. UP-NS will have until July 27 to provide that information. The board also ruled that a full environmental impact study would need to be completed before the merger could proceed.

“The Board finds that there are several aspects of the revised application that are unclear or underdeveloped and require supplementation at this stage of the proceeding so that the Board may have the information necessary to thoroughly evaluate — and the public has an adequate opportunity to comment on — whether the transaction is in the public interest,” the regulator said in a statement.

The STB did not establish a procedural schedule, but with the board requesting more information, it is unlikely UP-NS will meet its target of completing the merger by early 2027.

The Stop the Rail Merger Coalition — a group spearheaded by BNSF and CPKC — pounced on the fact that the STB asked for additional information, particularly about downstream merger impacts.

“UP and NS have once again submitted an extremely flawed proposal. They have overstated benefits, minimized harms, and left critical questions unanswered. This merger is a bad deal for America and must be rejected,” said the Stop the Rail Merger Coalition in a press release.

But UP officials said they were confident that they would ultimately succeed in creating North America’s largest railroad.

“We are confident this merger will deliver more reliable and lower-cost transportation options for American businesses,” said Union Pacific CEO Jim Vena. “We submitted a comprehensive, data-driven application backed by a detailed plan for seamless integration. We look forward to the opportunity to show the facts and demonstrate the benefits for our customers, employees and America.”

—Justin Franz