WASHINGTON — Randall L. Stephenson, AT&T’s chief executive, said on Friday that the company had made a “big mistake” by hiring President Trump’s personal lawyer, Michael D. Cohen, to provide advice on federal policy, including how the government might approach the telecommunications giant’s deal to buy Time Warner.
Mr. Stephenson also said that the company’s head of lobbying and external affairs, Bob Quinn, would be leaving the company.
“Our company has been in the headlines for all the wrong reasons these last few days and our reputation has been damaged,” Mr. Stephenson wrote in a memo to employees. “There is no other way to say it — AT&T hiring Michael Cohen as a political consultant was a big mistake.”
Mr. Stephenson’s note followed the revelation this week that the company had paid Mr. Cohen $600,000 to advise on the $85.4 billion merger with Time Warner and other regulatory matters.
Federal prosecutors are investigating Mr. Cohen’s business dealings, including a $130,000 payment he made to the adult film actress Stephanie Clifford, known professionally as Stormy Daniels, to buy her silence about an affair she says she had with Mr. Trump. The president has denied Ms. Clifford’s claims.
The payment to Ms. Clifford was the first known activity involving Essential Consultants, a company started by Mr. Cohen. It was through Essential Consultants that AT&T retained Mr. Cohen. Several other businesses, including the Swiss drugmaker Novartis and an American company linked to a Russian oligarch, also sent payments to Mr. Cohen’s company.
The Russian, Viktor Vekselberg, was stopped and questioned at an airport this year by investigators for Robert S. Mueller III, the special counsel examining Russian interference in the 2016 presidential election.
Although AT&T’s statements were meant to distance itself from Mr. Cohen and the arrangement on Friday, they also provided insight into how companies like AT&T operate in Washington during the Trump era.
Mr. Trump pledged during his campaign to shake up the Washington establishment — to “drain the swamp” — while railing against “the special interests, the lobbyists and the corrupt corporate media that have rigged the system against everyday Americans.” He also announced policies intended to clamp down on the revolving door between government and K Street, which is home to many of the capital’s lobbying firms.