WASHINGTON (Reuters) -Senate Democratic Leader Chuck Schumer criticized Union Pacific's plan to acquire Norfolk Southern in a $85 billion deal to create the first U.S. coast-to-coast freight rail operator.

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

The Surface Transportation Board said on Wednesday that Union Pacific and Norfolk Southern have formally filed a notice of intent to combine, triggering the U.S. regulatory review process for a proposed $85 billion merger between the two major railroads.