It is not known which complaint, if any, triggered the New York court’s investigation.
Mr. Giuliani is also licensed to practice law in Washington, D.C., and the decision in New York could set off disciplinary proceedings there, although that is not automatic.
Although Mr. Giuliani started his own law firm in 2019, it has been decades since he regularly argued in courtrooms.
Still, the suspension marked another stunning chapter in the rise and fall of Mr. Giuliani, once a legal and political star.
He had enjoyed near-hero status when, as New York City mayor, he led the city through the Sept. 11, 2001, terrorist attacks.
The federal investigation into Mr. Giuliani centers on his dealings in Ukraine before the 2020 election, when he sought to damage President Biden’s credibility.
In April, F.B.I. agents seized Mr. Giuliani’s cellphones and computers, an extraordinary action to take against a lawyer for a former president. »
