UPDATE 1-U.S. judge questions whether Trump can block Twitter users

(Adds details throughout from court hearing)

NEW YORK, March 8 (Reuters) - A federal judge on Thursday expressed skepticism about whether U.S. President Donald Trump can constitutionally block Twitter users whose views he does not like from following and retweeting from his own Twitter account.

At a hearing in Manhattan federal court, U.S. District Judge Naomi Reice Buchwald asked Trump's lawyer Michael Baer whether letting Trump bar users from zrealDonaldTrump would violate their First Amendment free speech rights.

She asked whether Twitter was different from a public town hall, where government officials would be unable to pull the plug from a microphone to mute speakers with unwelcome views.

"Once it is a public forum, you can't shut somebody up because you don't like what they're saying," Buchwald said.

Baer said the appropriate analogy was not a town hall, but rather Trump choosing to walk away from someone at a public event.

"The president has an associational interest in deciding who he's going to spend his time with in that setting," he said.

Buchwald scheduled the hearing to consider Trump's request to dismiss a lawsuit filed in July over his use of Twitter by the Knight First Amendment Institute at Columbia University and several Twitter users.

They said Trump's account is a public forum, and that the president cannot block Twitter users simply because they criticize, mock or disagree with him in replies to his tweets.

Trump's Twitter use draws intense interest for his unvarnished commentary, including attacks on critics. His tweets often shape news and are retweeted tens of thousands of times.

Baer, who works for the U.S. Department of Justice, has also argued that Trump's use of Twitter was personal, and did not qualify as a "state action."

In contrast, Katherine Fallow, a lawyer for the plaintiffs, told Buchwald the record "shows unambiguously that the president operates his account in an official capacity."

She said Trump often uses Twitter to announce policies or policy proposals, such as banning the military from accepting transgender recruits.

Twitter lets users post snippets of text, called tweets, to which other users may respond. When one user blocks another, the blocked user cannot respond to the blocker's tweets.

It is not clear when Buchwald will rule. (Reporting by Brendan Pierson in New York; Editing by Susan Thomas and Tom Brown)