Union Pacific Corp. agreed to acquire Norfolk Southern Corp. in a $72 billion cash-and-stock transaction, forming the only US transcontinental railroad in what stands to be the industry’s largest deal ever.

The Union Pacific and Norfolk Southern corporations announced Tuesday the companies will merge to create America's first transcontinental freight railroad.

Union Pacific , the largest U.S. railroad operator, could reach an agreement to acquire rival Norfolk Southern as soon as early next week, Bloomberg News reported on Friday, citing people familiar with the matter.