** Shares of Norfolk Southern NSC.N up 3% at $278 in morning trading
** Union Pacific UNP.N exploring deal to buy NSC, Wall Street Journal and Financial Times reported late on Thursday
** Deal would create a rail giant with combined market value of about $200 bln; expected to face regulatory scrutiny, including from the Surface Transportation Board
** "A unified transcon network would eliminate redundant interchanges for cross-country freight, enhancing efficiency and improving key operating metrics like velocity and dwell time," Jefferies analysts wrote in a note, calling the strategic benefits of such a merger 'compelling'
** The merger would expand UNP's reach to the eastern U.S., adding NSC's 19,500-mile network across 22 states
** YTD, NSC up ~15% and UNP down 0.24%