A judge ruled in favor of a husband and wife suing Mast Capital over the sale of their condo at a waterfront Miami Beach building the developer has attempted to buy out.

In an order entered on Wednesday, Miami-Dade Circuit Court Judge Migna Sanchez-Llorens ruled that Mast breached its contract with the sellers, Clifford and Maria Greenhouse. Sanchez-Llorens, who granted a partial summary judgment in favor of the Greenhouses, also denied the defendant’s cross-motion.

The lawsuit, filed the summer of 2023, alleged that Mast breached its contract and failed to fund the remainder of the deposit to buy the Greenhouses’ unit. The complaint also alleged that the language in their sale agreement with Mast affiliate 5313 Collins Acquisitions LLC allows the developer to extend the closing date in perpetuity.

The Greenhouses claimed they could be “in legal limbo … forever bound by a contract under which the other party had no deadline for its performance,” the complaint alleged.

They entered into a contract to sell their unit to Mast in 2021 for $650,000. The sale was supposed to close in November 2022. It has yet to close.

Mast Capital, led by Camilo Miguel Jr., and the firm’s attorneys did not respond to requests for comment.

Coconut Grove-based Mast planned to buy out the unit owners of the 120-unit Amethyst condo building at 5313 Collins Avenue, The Real Deal previously reported. But the developer dragged out the closings for a number of units and kept the sellers locked into contracts in an attempt to get them to sell to Mast for lower prices, sellers alleged.

Property records show the Mast affiliate has closed on 32 units at the 11-story condominium. That represents about a quarter of the building. Five of those sales were recorded between November 2023 and December 2024 for undisclosed amounts, records show.

Mast’s ability to acquire the majority of condos is contingent on purchase agreements with a group of condo owners that at one point included 28 condos. Those contracts are contingent on each other closing, meaning if Mast acquired one, it had to acquire all — a provision that remains in effect for two years after a cancellation.

Mast and its partner, Barry Sternlicht’s Starwood Capital Group, are developing the site next door into the Perigon, a luxury oceanfront condo. Mast completed a bulk buyout of the building that previously sat on that property.

Robert Pelier, the Greenhouses’ attorney, said the judge’s ruling sends a message to the developer. Other sellers believe they are “stuck in the same scenario,” he added.

“[Mast] can’t be whimsical about their provisions and their responsibilities under the contract,” Pelier said.

The judge’s order points to Mast’s response, stating that it received no notice of default from the sellers, but in the same filing said it received a notice of default from the sellers’ attorney.

In a deposition of Jordan Kornberg, chief investment officer at Mast, Kornberg acknowledged the Greenhouses were owed about $14,500 in deposit funds, per their contract.

Pelier said his clients planned to simultaneously close on the sale of their condo at the Amethyst and close on an unspecified new purchase. They are seeking damages that would include the deposit they lost on a planned purchase in 2022.

If the Greenhouses move forward on the other counts, the judge would rule next on whether Mast crafted an “unenforceable contract” that simultaneously sets time limits and allows the developer to perpetually extend the closing date, Pelier said.

The latest ruling, he said, “strengthens our position in that regard.”