CSX, Norfolk up on report they are likely buyout targets, suitor Union Pacific drops

** Union Pacific UNP.N down 1.3% premarket; CSX CSX.O up 4.5% and Norfolk Southern NSC.N up 2.6%

** UNP working with Morgan Stanley to explore an acquisition of a rival, Semafor reported Wednesday

** Report says merger would mean combining with one of two East Coast carriers: CSX or Norfolk Southern

** As of last close, S&P 500 Rail Transportation sub index .SPLRCRAIL up nearly 4% YTD

** UNP up 1.4% YTD, less than NSC at ~11% and CSX at ~3%