Union Pacific and Norfolk Southern are facing pressure from rival railroads BNSF and Canadian National, who told the Surface Transportation Board that the companies are withholding key documents needed to evaluate their proposed transcontinental merger, reported New York's FreightWaves.

In filings, BNSF and CN stated that the STB cannot properly assess the merger's impact on competition without more internal records. Both railroads asked the regulator to compel UP and NS to produce board presentations, adviser analyses, and internal emails.

BNSF argued that the review schedule should be paused until the documents are provided. It stated that the withheld material could reveal whether executives privately acknowledged risks such as reduced service, higher rates, or failed integration.

CN took a narrower stance, claiming that UP and NS withheld Schedule 5.8 of their merger agreement. This document likely outlines how the companies assessed regulatory risk, potential divestitures, and remedies. CN's legal chief, Olivier Chouc, emphasized that transparency is critical given the scale of the deal.

CN also asserted that the omission leaves the 6,692-page merger application procedurally incomplete under STB rules. The regulator is expected to decide shortly whether the filing is sufficient or must be resubmitted.

Both BNSF and CN warned that UP and NS's public statements may not align with internal discussions. CN added that the application lacked market analyses, traffic projections, and competitive proposals. Canadian Pacific Kansas City has backed CN's motion.

Union Pacific stated that it stands by its application. Spokeswoman Kristen South expressed confidence in its merits and affirmed that the company will continue working with the STB during the review process.