A group of attorneys general from six U.S. states has urged the Surface Transportation Board (STB) to reject the revised merger proposal between Union Pacific and Norfolk Southern, citing ongoing concerns about competition and transparency.

According to officials, the merger could reduce rail competition, limiting shippers' routing options and weakening their negotiating position. They also warned that consolidation may lead to higher transportation costs, ultimately increasing prices for businesses and consumers.

The letter highlights that the revised application lacks clarity, with key information on market shares and competitive impacts either incomplete or difficult to interpret. In addition, the proposal does not sufficiently explain how jointly owned assets, such as major terminal railways and shared railcar pools, would be managed, raising concerns about fair access and network neutrality for shippers.

The attorneys general also noted that the proposed divestitures are not clearly defined, as essential details, such as buyers and transaction terms, are missing. Furthermore, the application reportedly fails to assess how the merger could trigger further consolidation in the rail industry.

A final decision from the STB is expected soon, with shippers closely monitoring the outcome due to its potential impact on costs, service options, and market access.