Regulators aim to rewrite rules for big mergers.

WASHINGTON — Top federal antitrust officials on Tuesday announced a review of how they approve mergers and acquisitions, in a broad effort to strengthen enforcement and clamp down on a surge of corporate consolidation, particularly in high tech.

Lina Khan, chair of the Federal Trade Commission, and Jonathan Kanter, head of antitrust at the Justice Department, said they wanted to rewrite the merger guidelines created a dozen years ago because they didn’t directly address the unique problems raised by the tech industry.

The review will focus on how the merger review process is applied to free services, such as those from Google and Facebook. Often, price increases are a key measure for anticompetitive conduct, but that standard doesn’t apply to advertising-based business models that offer free services to consumers. The regulators will also look at how nascent rivals could be affected by a merger. The F.T.C., for instance, is suing to break up Facebook over its acquisitions of Instagram in 2012 and WhatsApp in 2014, when those services weren’t clearly direct competitors to Facebook.

Democratic regulators and lawmakers are racing to fulfill promises to curtail the dominance and power of a handful of tech giants, including Amazon, Apple, Facebook and Google. A Senate panel is expected to vote this week on legislation aimed at preventing powerful digital platforms such as Apple’s App Store and Amazon’s marketplace from blocking competitors.

President Biden has told the agencies to review the guidelines as part of his effort to strengthen the enforcement of merger rules. He picked vocal critics of technology giants to lead antitrust efforts, but the agencies led by Ms. Khan and Mr. Kanter have struggled to keep up with a surge of corporate acquisitions. Global mergers were valued at a record total of $5.8 trillion in 2021, and the caseload for merger reviews at the F.T.C. and Justice Department has doubled, Ms. Khan said.

The regulators said they were also interested in broadening the scope of antitrust enforcement to consider potential ripple effects of corporate concentration on labor markets, innovation and consumer protection.

“This inquiry launched by the F.T.C. and D.O.J. is designed to ensure that our merger guidelines accurately reflect modern market realities and equip us to forcefully enforce the law against unlawful deals,” Ms. Khan said.

Last year, the F.T.C. began a review of guidelines for so-called vertical mergers — the acquisition of companies’ adjacent markets that are part of a supply chain. Tech companies have acquired scores of companies that don’t directly compete with their main businesses, but that have helped giants like Facebook, Amazon and Google spread their tentacles into new markets and maintain their dominance, leaders including Ms. Khan and Mr. Kanter have argued. The announcement by Microsoft, whose main business is in enterprise and consumer software, on Tuesday that it would buy game maker Activision Blizzard for nearly $70 billion is an example of this activity. Regulators declined to comment on the deal.

The regulators may face challenges to revised rules in the courts. Judges have adhered to decades-old interpretations of antitrust laws that hold consumer prices as the primary test of monopolization. The agencies are expected to take about one year to rewrite its merger rules.