Union Pacific Corporation (NYSE: UNP) and Norfolk Southern Corporation (NYSE: NSC) reported two developments in their proposed railroad merger, according to a joint press release.

The Surface Transportation Board (STB) unanimously rejected requests from merger opponents to dismiss the companies' revised merger application, allowing the board to continue its review of the transaction. The two railroads said the STB's decision permits the review process to proceed.

Separately, the International Association of Sheet Metal, Air, Rail and Transportation's Railroad Mechanical Department (SMART-MD) signed a jobs-for-life agreement with the two railroads. The agreement is described as protecting represented jobs and preserving work opportunities for union members. The companies stated that with SMART-MD's support, more unions representing their employees now support the merger than oppose it.

The merger application claims the combined railroad would eliminate time-consuming interchanges between rail carriers, convert 10,000 existing interline lanes to single-line service, and create seven new premium intermodal lanes. The application also states that every union employee at the time of merger approval would retain their job for life and that all existing gateways would remain open.

"The momentum behind this transaction continues to build, and we are ready to keep moving forward," said Union Pacific CEO Jim Vena.

Norfolk Southern President and CEO Mark George said the STB decision "marks another important step in bringing Union Pacific and Norfolk Southern together."

The transaction remains subject to STB review and approval. The companies expect the transaction to close in the second half of 2027.