San Jose Mayor Chuck Reed said Tuesday he would consider softening the city’s recently approved medical marijuana ordinance after critics succeeded in qualifying a referendum to repeal the new rules.

The ordinance the City Council approved in September would shrink the number of medical marijuana collectives allowed in the city from more than 100 to just 10, in addition to requiring them to grow all of the marijuana they distribute on site.

Critics collected more than 49,000 signatures in a month to repeal the law, which they argued would require the creation of marijuana superstores that federal drug agents would shut down.

Reed had said after the petitions were submitted last year that if the medical marijuana activists qualified a referendum he was inclined to let city voters decide on the ordinance in June. He also asked that the council at next week’s meeting raise the city’s tax on medical marijuana collectives from 7 to 10 percent to cover election costs.

But the mayor said Tuesday he’d consider allowing more pot clubs and otherwise modifying the ordinance to address critics’ concerns.

“There are some changes I could support,” Reed said. “The question is whether a council majority will support them. My preference is that we can negotiate some kind of ordinance that we can all live with.”

The petition needed at least 29,653 valid signatures, representing 8 percent of registered voters in San Jose, to qualify a referendum. A sample examination by the Santa Clara County Registrar of Voters in November initially led city officials to believe the petition had qualified without the need to check the whole batch of signatures. But that proved not to be the case.

After scrutinizing the entire petition, however, the registrar’s office concluded Dec. 30 that there were 31,103 valid signatures.

“We’re very gratified that the voters wanted us to look at this and find something more workable,” said James Anthony, chairman of the Citizens Coalition for Patient Care, which raised $200,000 in a month for the referendum drive.

The ordinance has been suspended since the petition was submitted. And now that the petition has qualified a referendum, the council either must put the matter on the ballot at the next regularly scheduled municipal election in June, call a special election or repeal the ordinance.

The law’s critics want the city to repeal the ordinance and replace it with something more to their liking.

A medical marijuana referendum might be an unwelcome addition to a June city ballot for which Reed is seeking a vote on his controversial pension reform measure. And if Major League Baseball in the coming weeks gives the Oakland A’s permission to move to San Jose, as has been widely rumored, a ballpark vote also could also end up on the ballot.

San Jose became the largest Northern California city to approve regulations allowing medical marijuana collectives with the council’s 8-3 vote on the ordinance in September. The drug remains illegal under federal law, and the U.S. attorney’s office has stepped up prosecutions in recent months in response to a proliferation of pot clubs that prosecutors characterize as nothing more than dope dealers.

Reed said he would consider more than doubling the number of city-allowed pot clubs to as many as 25, the number recommended by the city’s planning commission, as well as permitting some off-site cultivation. He also said he’d consider a different process for winnowing down the number of shops.

The ordinance called for the first 10 pot clubs to submit qualified applications online to be approved. City administrators said the idea was to avoid the cost and delay of a formal bidding process.

But critics complained that a “first-come” system wouldn’t ensure that the most responsible operators were chosen.

All of the storefront collectives are technically illegal under San Jose law because the city doesn’t have any zoning that allows them. The council in September also approved zoning to allow medical marijuana collectives in certain commercial and industrial areas, but suspended the new zoning pending implementation of the regulations that were challenged by the referendum.

Reed said he’ll call for the council to postpone any decision on the marijuana law and tax until its Jan. 24 meeting to allow council members time to consider a compromise.

“We’re still hopeful,” Anthony said, “that we can come to some workable arrangement with the City Council.”

Contact John Woolfolk at 408-975-9346.