(Reuters) - The U.S. has sued to block a proposed merger between American Express Global Business Travel Group and CWT Holdings, saying the $570 million deal would eliminate competition between the largest and third largest providers of business travel management services.

The deal threatens to undermine competition for those services in the U.S., the Department of Justice said in the lawsuit filed in Manhattan federal court on Friday.

"American businesses will face the consequences, seeing higher prices, less innovation and fewer choices," Doha Mekki, head of the DOJ's Antitrust Division, said.

A spokesperson for GBTG did not immediately respond to a request for comment. A spokesperson for CWT declined to comment.

GBTG executives viewed the deal as an opportunity to absorb what they viewed as a "dangerous competitor," prosecutors said in the complaint.

GBTG handled $28 billion of travel transactions in 2023, and has acquired several other travel companies in recent years, according to prosecutors.

American Express has a minority stake in GBTG, which operates as a separate company.

The deal announced in March had elicited concerns from British antitrust authorities.