CHICAGO (Reuters) - Chicago Mayor Rahm Emanuel said Friday he would back a proposal that would decriminalize possessing small amounts of marijuana, the latest major U.S. political figure to support diminished penalties for the drug’s use.

Under the proposed ordinance, to be voted on by the city council later this month, police officers in the nation’s third-largest city would be able to issue a written violation for possession of 15 grams or less.

This is a modified version of an ordinance proposed last fall by a group of Chicago aldermen, who said the measure would help raise revenue for the city, save money and free up police to pursue more serious crimes.

More than a dozen states and several of the largest U.S. cities have already taken similar steps. New York State Governor Andrew Cuomo is another supporter of pot decriminalization.

Chicago Police Department statistics indicate that last year there were 18,298 arrests for possession of less than 10 grams of marijuana, according to a statement from the mayor’s office. Each case involves approximately four officers - two arresting and two transporting officers - and places an additional burden on the Cook County court and jail system, the statement said.

“These arrests tied up more than 45,000 police hours,” Police Superintendent Garry McCarthy said in the mayor’s office statement. “The new ordinance nearly cuts that time in half, which equals an approximate $1 million in savings, while freeing up cops to address more serious crime.”

Currently, those caught with small amounts of the drug could face up to six months in jail. The aldermen’s original ordinance set the limit at 10 grams.

When the ordinance was first introduced last year, Emanuel, who was President Barack Obama’s first White House chief of staff, had said he would ask the police to do an analysis to see if the reform would make sense.

“The result is an ordinance that allows us to observe the law, while reducing the processing time for minor possession of marijuana - ultimately freeing up police officers for the street,” Emanuel said.

McCarthy and Emanuel have been under pressure in recent weeks to quell a spike in gun violence in Chicago. Through May 13 of this year, there have been 185 homicides in the city, up from 116 during the comparable period last year, and the numbers have continued to rise. Emanuel had vowed to cut the city’s crime rate when he was elected last year.

Fifteen states have reduced the penalty for possession of limited amounts of marijuana, according to Allen St. Pierre, executive director of NORML, a lobbying group working to legalize the drug. Other cities with similar policies include Seattle, Pittsburgh and Philadelphia, as well as university towns like Champaign, Illinois, and Madison, Wisconsin. Seventeen states and the District of Columbia have legalized medical marijuana.

“It’s a pragmatic move,” said St. Pierre, regarding Emanuel’s decision.

Under a New York proposal approved by the State Assembly Wednesday and backed by Cuomo, patients could buy marijuana at pharmacies and hospitals or from non-profits certified by the state. The Republican-led New York Senate is not expected to allow a vote on the bill this session.

Opponents of decriminalization have argued that it normalizes drug use, and results in a lost opportunity for intervention.

The Chicago ordinance will likely be voted on during the City Council meeting June 27.