" Berkshire Hathaway's (BRK.A) (BRK.B) BNSF Railway has asked the U.S. Surface Transportation Board to immediately review, enforce, and potentially modify the competitive conditions the board imposed nearly 30 years ago when it approved Union Pacific's (UNP) acquisition of Southern Pacific.

The original conditions set with the merger granted BNSF certain rights, such as access to "2-to-1" customer locations where Union Pacific (UNP) and Southern Pacific previously competed to preserve shipper choice after the merger consolidated two major Western railroads.

In its new petition, BNSF is effectively asking the regulator to reopen that record, examine how those conditions have actually functioned in practice, and step in to ensure that the promised level of competition is genuinely available to customers in the current market. The railroad also proposed a defined review schedule so parties can build a full evidentiary record and the board can act within a set timeframe.

The main rationale BNSF offered up is that Union Pacific (UNP) has spent much of the past three decades undermining rather than honoring the merger commitments from the Union Pacific (UNP)-Southern Pacific combination. BNSF alleges a pattern of obstructive conduct, including delaying or denying interchange access, imposing unreasonable operational requirements, resisting updates to trackage-rights agreements, and generally making it harder for BNSF to provide competitive service where the board intended it to replace lost Southern Pacific competition.

Union Pacific's (UNP) 1996 acquisition of Southern Pacific created the nation’s largest freight railroad at the time. The 35,000-mile Western network was approved by regulators as an "efficiency" merger but was followed by periods of severe service disruptions, congestion, and ongoing controversy over the long-term impact on rail competition."