Union Pacific Bid Values Norfolk Southern at About $320 a Share

Union Pacific Corp. is nearing an agreement for a stock-and-cash deal for Norfolk Southern Corp. that would value the smaller rival at about $320 a share, people familiar with the matter said, in what would be the rail industry’s biggest-ever tie-up.

The offer would be comprised of about two-thirds stock and one-third cash, said the people, who asked not to be identified because the information is private. At $320 a share, Norfolk Southern’s equity value would be about $72 billion, according to Bloomberg calculations.