The U.K. Competition and Markets Authority’s decision to block Microsoft’s $69 billion acquisition of video game maker Activision on Tuesday could have a chilling effect on other tech industry mergers.

“I think that the DOJ and FTC’s new attitude toward tech, antitrust and mergers already had a chilling effect to some extent,” Daniel Crane, a professor at the University of Michigan School of Law, said, referring to two U.S. federal agencies—the Department of Justice and the Federal Trade Commission.