WASHINGTON—U.S. antitrust enforcers announced plans on Tuesday to rewrite merger guidelines in order to better fight illegal deals. The U.S. Justice Department and Federal Trade Commission issued a joint statement saying U.S. industries had become increasingly concentrated and a surge in merger filings in 2020 and 2021 signaled the situation will worsen. In the statement, FTC Chair Lina Khan cited a need to prevent price rises and prevent companies from pushing wages down. She said the agencies were soliciting public opinion on how best to address this. Jonathan Kanter, head of the Justice Department’s Antitrust Division, said the government wanted to “think carefully about how to ensure our merger enforcement tools are fit for purpose in the modern economy.” The FTC and Justice Department had said in July, when the Biden administration issued a competition executive order, that they would soon launch a review of merger guidelines to determine if …