AT&T CEO Randall Stephenson called the hiring of President Donald Trump’s personal lawyer, Michael Cohen, damaging to the company’s reputation and a “big mistake.”

Stephenson made the admission in a memo circulated to employees on Friday, which announced that AT&T’s lead lobbyist, Bob Quinn, who oversaw the hiring of Cohen, would be retiring.

“Our company has been in the headlines for all the wrong reasons these last few days and our reputation has been damaged,” Stephenson wrote to employees in a memo obtained by Deadline. “There is no other way to say it — AT&T hiring Michael Cohen as a political consultant was a big mistake.”

The wireless carrier hired Cohen’s firm, Essential Consultants, within days of Trump being sworn in to provide advice on a range of issues, including the company’s pending $85 billion acquisition of Time Warner. AT&T entered into a $600,000 contract with Cohen specifying he would provide advice on the merger, which would require the approval of federal regulators.

It’s not entirely clear what particular insights Cohen, a personal injury lawyer, real estate investor and taxi cab owner, would bring to antitrust matters — other than his ties to Trump, the Washington Post observed.

AT&T has said that Cohen’s firm was among several consultants brought on to help the company understand how the newly elected president would approach issues important to the company, including its Time Warner deal.

Cohen approached AT&T’s external affairs in the transition period following the 2016 presidential election saying he would leave the Trump Organization and perform consulting for a few companies who wanted his insights into how the new President and key players think, the wireless company told its employees.

AT&T said it entered into a one-year contract paying $50,000 a month, from January through December 2017, that limited the scope of Cohen’s work to consulting and advisory services, but did not permit lobbying, the company said.

That’s an important distinction, because Cohen was not a registered lobbyist.

“To be clear, everything we did was done according to the law and entirely legitimate,” Stephenson said in a memo, which was first reported by Reuters. “But the fact is, our past association with Cohen was a serious misjudgment. In this instance, our Washington D.C. team’s vetting process clearly failed, and I take responsibility for that.”

AT&T’s payments to Essential Consultants were disclosed by Michael Avenatti, adult film actress Stormy Daniels’ lawyer.