A simmering feud between Miami and the agency that will manage the parking garages at the Miami Marlins’ new Little Havana ballpark is making it more unlikely that ground-floor retailers will set up shop by Opening Day in April 2012.

The city, which is building the garages, and the Miami Parking Authority, which will operate them, have yet to agree on the fine print of a deal laying out how the garages will be run. Potential retail and restaurant tenants can’t sign leases until the two sides have inked the agreement, which hands control of the garages to the parking authority to serve as landlord.

City commissioners put forth a proposed contract two weeks ago after a commercial real-estate broker warned that time is tight for businesses to open their doors in the four months left before Opening Day. To speed up the process, the semi-autonomous parking authority set a special board meeting for Wednesday to finalize the deal.

But at the meeting, board members added a wrinkle that will cause an additional delay: They voted unanimously for the agreement — only if the city first agrees to a pair of changes.

To protect the parking authority’s interests, the board wants to make sure the agency is not on the hook for covering any potential budget shortfall in operating the garages, and that the MPA, like the city, can terminate the agreement at any time. Neither provision was spelled out in the city’s contract.

The changes will push back the signing of any leases by at least another two weeks, when city commissioners meet again, further diminishing the chances that any retail stores will be up and running in the garages by the start of baseball season. No restaurants, which take considerably longer to set up, will be open, either.

“It’s already taken too long, so why exacerbate the problem?” Art Noriega, the parking authority’s CEO, told board members in an effort to get them to back the city’s deal.

Noriega and Assistant City Manager Alice Bravo tried to reassure the board that if they signed the agreement as is, they still could pursue any changes before the commission later.

That suggestion did not sit well with the skeptical board, still smarting over the city’s failed attempt last year to take over the parking authority, a move rejected by voters at the polls.

“I don’t want to sit here and be fed a lot of B.S., because that’s what this is,” said Jami Reyes, the board’s chairwoman. “I’m afraid that once we say yes, we’re done, that’s it. I don’t trust anything that we’re told.”

Commissioner Frank Carollo, whose district includes the garages and the ballpark, has blamed leasing delays on turnover of the city manager post and other senior staff positions.

But Wednesday, Carollo said he wasn’t all that concerned over the latest hiccup.

“Obviously I would have preferred that it got voted on the way the city commission sent it,” he said. “But they’re a board, and I respect that they made amendments.”

If there’s a silver lining to not having fully-leased spaces by the first Marlins home game, Noriega said, it’s that his agency will get to focus on one thing: parking.

“The worst thing we want to have happen is we get to Opening Day and it takes people an hour to get out of the garage,” he said. “We’re never going to get back that first impression.”