The US Senate appointed former corporate lawyer and lobbyist Makan Delrahim to be the Department of Justice’s (DoJ) new antitrust chief.

Delrahim was nominated by President Donald Trump in March, but his appointment was delayed by Democrats over concerns about potential conflicts of interest given his professional history. In the past, Delrahim represented companies including T-Mobile US, AT&T, Apple, Google, Qualcomm and Microsoft.

Despite those concerns, AT&T’s merger with content company Time Warner is likely to be one of the first cases on Delrahim’s agenda.

A response to a question from Senator Diane Feinstein in May hinted at the the new chief’s view of such deals: “the majority of antitrust scholars recognise that most vertical mergers raise less serious competition concerns than horizontal mergers”, he said.

However, Delrahim also acknowledged there are cases where a vertical merger could have “anticompetitive effects” and said it would be critical to assess whether there is the possibility of “harm to consumers flowing from the proposed transaction”.

Delrahim will also likely helm a review of any merger deal between Sprint and T-Mobile. During questioning in May, Delrahim said he did not have “any particular impression” regarding the state of wireless competition in the US market.

The Federal Communications Commission this week declared the mobile market sufficiently competitive for the first time since 2009.

Delrahim previously said he will work with ethics officials to address potential conflicts in cases involving “past clients, and clients of my former employer, my law firm”. The comment indicates he may yet recuse himself from any matters involving either AT&T or T-Mobile.

Responding to questions for the record sent by Senator Feinstein in May, Delrahim said his focus as head of the DoJ’s Antitrust Division will be on addressing: “cartel behaviour that raises prices or otherwise adversely affects the welfare of consumers; mergers and other forms of consolidation that risk a substantial lessening of competition; and single firm or collusive conduct that suppresses the free market competition to which consumers are entitled”.

Delrahim also addressed concerns from Senator Patrick Leahy about his independence from President Trump, noting investigations should be conducted “without regard to political considerations”.