The merger would create the United States’ first coast-to-coast rail network, spanning 50,000 miles and 43 states.

A number of stocks fell in the afternoon session after bellwether United Parcel Service (UPS) reported weak earnings and withheld its full-year guidance, citing “macro-economic uncertainty” and low consumer sentiment.

Atlanta-based Norfolk Southern and Union Pacific have agreed to a merger that would create the first transcontinental railroad in the U.S.