WASHINGTON (Reuters) - The chair of the U.S. House of Representatives antitrust subcommittee pressed top regulators on Tuesday over merger decisions, including the Justice Department's approval of T-Mobile US Inc's TMUS.O proposed purchase of Sprint Corp S.N.

FILE PHOTO: Representative David Cicilline, a Democrat from Rhode Island, speaks during a House Judiciary Committee hearing in Washington, D.C., U.S. December 12, 2019. Alex Edelman/Pool via REUTERS

Congressman David Cicilline raised antitrust questions as activists and Democratic presidential candidates are advocating for more aggressive enforcement of rules governing market concentration and corporate behavior.

In questions posted on a House website, Cicilline asked Makan Delrahim, head of the Justice Department's Antitrust Division, about text messages he had sent to Dish Network Corp DISH.O Chairman Charlie Ergen, who plans to buy assets that T-Mobile and Sprint would sell as part of an agreement to win federal approval for their deal.

The planned merger of the third and fourth largest wireless providers is being challenged by state attorneys general, led by California and New York. A trial in New York is underway.

Cicilline noted that Delrahim wrote to Ergen: “Today would be a good day to have your Senator friends contact the chairman,” a reference to the chair of the Federal Communications Commission which has since approved the merger.

Cicilline asked Delrahim if he had offered lobbying advice to other merging companies and if it was appropriate to offer such advice.

Cicilline also pressed the antitrust chief on a report that the Trump administration has brought fewer criminal antitrust cases, essentially price-fixing, than any in 50 years. “Is it your view that market participants are no longer engaging in price-fixing at the rates they previously had?” Cicilline asked.

Cicilline asked Federal Trade Commission Chairman Joe Simons about the November approval of Bristol-Myers Squibb Co's BMY.N $74 billion purchase of Celgene on the condition it divest the drug Otezla.

Cicilline asked the agency whether its practice of focusing on product overlap is enough when analyzing this and other pharmaceutical mergers.

Cicilline also pressed Simons on the FTC's record $5 billion settlement with Facebook Inc FB.O for the social media company's violation of an earlier settlement with the agency. He cited criticism that Facebook Chief Executive Mark Zuckerberg was not held responsible for the order violations.

“What is the Commission doing to ensure that CEOs of large companies are held accountable when their companies violate antitrust law with the CEOs’ knowledge or at his or her direction?,” Cicilline asked.

An FTC spokesman declined to comment. A Justice Department spokesman did not immediately respond to a request for comment.