However, just two years ago, the STB approved the first major rail merger in more than two decades. In that deal, which was supported by big shippers, Canadian Pacific acquired Kansas City Southern for US$31-billion to create the CPKC railroad.

Union Pacific and Norfolk Southern confirmed that they are in “advanced” merger talks that would create a single US railroad with service stretching from the East to the West Coast. The Associated Press reported last week that the companies were discussing a tie-up but neither company acknowledged that until Thursday morning.