 Shares of railroad operators fell Wednesday, helping drag the Dow Jones Transportation Average DJT, -1.02 down by 1.3 in midday trading despite a 39-point gain in the Dow Jones Industrial Average DJIA, 0.13 and 0.3 rise in the SP 500 SPX, 0.29 , amid concerns over a possible labor strike. Shares of Union Pacific Corp. UNP, -4.53 shed 4.8, Norfolk Southern Corp. NSC, -2.74 dropped 2.8 and CSX Corp. CSX, -2.42 slumped 2.6. 