* Messages under seal, request for stay set for next week

* Protester arrested on Brooklyn Bridge in October 2011

* Occupy movement set to mark anniversary on Monday

(Adds details from court, background, quotes)

NEW YORK, Sept 14 (Reuters) – Twitter handed over tweets
from an Occupy Wall Street protester to a New York criminal
judge on Friday after months of fighting a subpoena from
prosecutors in a closely watched case pitting privacy and free
speech advocates against law enforcement.

The company surrendered the micro-blogging posts – an
inch-high stack of paper inside a mailing envelope – to
Manhattan Criminal Court Judge Matthew Sciarrino. They will
remain under seal while a request for a stay by the protester,
Malcolm Harris, is heard next week in a higher court.

Harris, 23, was one of hundreds arrested during a mass
protest on the Brooklyn Bridge in October 2011. The Manhattan
district attorney's office wants the tweets, which are no longer
available online, to try to undermine Harris' argument that
police officers appeared to lead protesters onto the bridge's
roadway only to arrest them for obstructing traffic.

Twitter and Harris had challenged the subpoena but Sciarrino
rejected their arguments in June. Twitter has filed an appeal,
which is scheduled to be heard in November.

The case involves a thorny legal question: whether Twitter
users have the right to fight in court requests from law
enforcement for their tweets.

Twitter had faced a Friday deadline to comply with the
subpoena or face contempt and a heavy fine.

In court on Friday, the company's lawyer asked the judge to
consider keeping the files sealed until the appeals court rules,
warning that its appeal could be deemed moot if prosecutors are
already in possession of the records. But Sciarrino refused.

Sciarrino did, however, urge the appeals court to take up
the question of when Twitter or its users can fight a subpoena,
even though Twitter has yielded the tweets.

"I strongly encourage the appellate court … to decide the
case on the merits, as I too agree that this is a more important
issue than maybe the trial itself," Sciarrino said.

Harris' lawyer, Martin Stolar, said he was disappointed that
Twitter had handed over the messages but vowed to continue to
challenge the subpoena.

"We're not giving up the fight here," he said following the
court session, as Harris stood by his side.

In addition to Twitter's appeal, Stolar has filed a civil
action claiming the judge overstepped his authority in ordering
the tweets handed over.

The surrender of Harris' tweets comes as the Occupy movement
prepares to mark its one-year anniversary next week.

Activists in the movement, which last fall sparked a
national conversation about economic inequality and coined the
catch phrase "We are the 99 percent," aim to surround the New
York Stock Exchange and stage a sit-in on Monday.

(Reporting by Joseph Ax; Editing by Bill Trott and Xavier