CSX shares jumped more than 7 percent to a record high on Wednesday after the rail transportation company reported quarterly results that topped analysts' expectations.

CSX reported per-share earnings of $1.01 in the second quarter, up 58 percent from the year-earlier period, and beating the 87 cents per share expected by analysts polled by Thomson Reuters. The Jacksonville, Florida-based company also generated $3.1 billion in revenue versus the $3 billion expected by analysts. CSX's revenue was boosted by a 2 percent increase in shipping volume for the quarter, topping a 0.9 percent forecast by StreetAccount.

CEO James Foote told analysts in a conference call Wednesday the strong performance last quarter was significantly driven by a lower corporate tax rate and a 6 percent reduction in shares outstanding. CSX' effective tax rate fell to 23.5 percent from 38.1 percent.

He also said the company's "great performance" contributed to CSX's results.

CSX's gains, along with a sharp jump in United Continental shares, helped lead the Dow Jones Transportation Average higher on Wednesday by more than 2 percent.

The company's shares had gained 17.1 percent through Monday's close, outperforming the Dow Transports. Through Monday, the index was down 1.4 percent.