NEW YORK, Dec 2 (Reuters) - New York officials were preparing for likely protests as a grand jury decides whether to charge police in the death of a black man subjected to a banned choke hold, but aimed to avoid the kind of violence that engulfed a St. Louis suburb last month.

Protest groups have planned marches if the grand jury does not charge any of the officers involved in the July 17 incident, which led to the death of Eric Garner, a 43-year-old father of six. It is not clear when the grand jury will rule.

Officials on Staten Island, the city's smallest borough and site of Garner's death, have been told to expect a heightened police presence in the wake of violent protests last week after a grand jury in Missouri did not charge a white police officer in the fatal shooting of an unarmed black teen in August.

Protesters may march to federal prosecutors' offices in Brooklyn, which some hope will take over the Garner case if there is no local indictment, according to activist Al Sharpton's National Action Network.

"We're just praying and hoping that things don't get out of hand," said Bobby Digi, a Staten Island activist and businessman. "We've been doing a lot of behind-the-scenes work to just try to get temperaments at bay."

After the Missouri grand jury decision in the death of Michael Brown, rioters clashed with police, burning down buildings and looting stores. The decision also prompted dozens of sympathy demonstrations across the United States, including in New York where major roadways were shut down.

Hazel Dukes, president of the New York state chapter of the NAACP civil rights group, said she was "very worried" about the possible response if no charges are brought by the Staten Island grand jury, which has been meeting in secret since August.

"We don't want to see rioting," Dukes said. "We don't want to see the destruction of our community."

New York Police Commissioner William Bratton met on Monday with Staten Island clergy and officials, who said afterward they were told to expect added police. A spokesman for Bratton did not respond to requests for comment on Tuesday.

Like the officer who shot Brown, the officer who put the choke hold on Garner, Daniel Pantaleo, is white.

DEMONSTRATIONS EXPECTED

New York police worked with police in Ferguson to share strategies and identify so-called professional agitators at protests, Bratton has told local media.

"When the decision comes, I expect, regardless of what the decision is, that there'll be some demonstrations," Staten Island District Attorney Daniel Donovan told reporters on Tuesday, noting that prior demonstrations had been peaceful.

Garner suffered a heart attack after officers compressed his neck and chest as they restrained him for selling loose cigarettes, the medical examiner ruled, calling his death a homicide.

Garner's health problems, including asthma and obesity, were contributing factors, the medical examiner said.

The incident, captured on a video that quickly spread over the Internet, fueled debates about how U.S. police use force, particularly against minorities.

The police department's patrol guide bans officers from using choke holds, saying they can be deadly.

Following the incident, Bratton vowed to overhaul training for the country's largest police force, while police union officials complained the department did not adequately train officers in how to restrain suspects without using choke holds.

The New York Civil Liberties Union also stood up for police, saying the department's telephone book-sized patrol manual offered insufficient detail on safe restraint techniques.

Garner's 18-year-old son, Eric Snipes, told the Daily News on Tuesday he did not expect violence.

"It's not going to be a Ferguson-like protest because I think everybody knows my father wasn't a violent man and they're going to respect his memory by remaining peaceful," Snipes said. "It's not going to be like it was there." (Editing by Scott Malone and Peter Cooney)