The Los Angeles City Council delayed a vote Wednesday on a medical marijuana ordinance that could close hundreds of pot dispensaries across the city.

The council asked planning officials to return next week with zoning maps that show how many pot dispensaries could close if the city bans the shops within 500 feet of homes, schools and public gathering sites.

The council is wrestling with setting that distance at 500 feet or 1,000 feet. Some members feel a 1,000-foot limit would banish pot clinics to industrial areas.

Council members indicated a vote could come in January on the law providing guidelines for pot dispensaries in the nation's second-largest city.

The city has fumbled previous attempts to adopt a pot law in the past two years.

"Let's just make a real informed decision," Councilman Ed Reyes said.

City officials estimate as many as 1,000 dispensaries operate in Los Angeles. Only four were open in 2005, when city officials first began discussing a local medical marijuana law.

Among the proposed provisions is capping the number of dispensaries at 70 a move that would shutter many shops that don't comply with the new law.

An estimated 137 dispensaries that registered before a moratorium was enacted in 2007 also would be allowed to remain open if they meet other requirements in the new law.

The 2007 moratorium was never enforced, with many pot clinics taking advantage of a hardship exemption that allowed them to open while awaiting city approval.

The proposed ordinance would allow cash reimbursement at the clinics, even though Los Angeles County District Attorney Steve Cooley has said he will go after pot dispensaries involved in over-the-counter sales.

Cooley interprets the state medical marijuana law as allowing only possession, use and cultivation of marijuana, but sales.

A Superior Court judge took a similar stance last week, signaling he would bar a dispensary from selling the drug because he believes it violates state law.

Fourteen states, including California, permit medical marijuana, but pot remains illegal under federal law.