A bipartisan pair of senators introduced legislation Friday aimed at stopping Big Tech companies such as Amazon, Facebook, and Google from acquiring smaller rivals.

Democratic Sen. Amy Klobuchar of Minnesota, the chairwoman of the Senate antitrust panel, and Republican Sen. Tom Cotton of Arkansas introduced the Platform Competition and Opportunity Act, a bill premised on the view that tech acquisitions — for example, Facebook buying rival platforms such as Instagram and WhatsApp in the past decade — have hurt consumer choices and competition. The bill would make major companies demonstrate that their proposed mergers aren’t anticompetitive.