The entrance to 300 Morse St. NE, part of the land near Union Market owned by the family of Sang Oh Choi, seen in 2006. The Choi family had tried to redevelop the area before the 2008 recession. (Len Spoden (703) 598-7427/FREELANCE)

Union Market may be just the beginning.

Landowners in the 24-acre wholesale market district in Northeast D.C. — often known as the Florida Avenue Market or Capital City Market — are laying the groundwork for an extensive new effort to redevelop more of the existing warehouses and wholesale storefronts into upscale housing and shopping.

In September, South Carolina-based developer Edensopened the first redeveloped part of the area, Union Market, a blend of high-end venders serving meats, cheeses, ice cream and prepared foods overseen by chef Richard Brandenburg. Last month, on the success of weekend crowds, Edens extended the market to five days a week from three.

But as Edens was lining up vendors for Union Market, it also negotiated the final details of a joint venture agreement with Sang Oh Choi, a Korean-American businessman whose family controls large portions of the market near the intersection of Florida Avenue and Fourth Street Northeast.

Choi and his family have been trying to redevelop portions of the market for years, despite major political and economic upheaval. In 2006, the D.C. Council passed legislation naming the Chois and Apollo Real Estate Advisors of New York, master developers of the entire market area over the complaints of dozens of individual shop owners — some of them families who owned their properties for generations — who weren’t interested in being bought out.

The Chois and Apollo (which since changed its name to Area Property Partners) formed a joint venture and planned a $1.2 billion “New Town” development, hired former at-large council member John L. Ray, known for his close ties to then-Ward 5 council member Harry Thomas Jr., to lobby the D.C. Council. In 2008, with the project faltering, Thomas proposed emergency legislation to try to hasten progress.

Shortly thereafter, prospects for the project crumbled as the economic downturn took a heavy toll. Then in May of this year, Thomas was sentenced to three years in a federal prison for stealing hundreds of thousands of dollars intended for youth programs. The Chois never broke ground.

Joining with Edens now appears to give the Chois another chance. Meanwhile, the Chois’ agreement with Area Property may collapse, according to a source familiar with the deal who was not authorized to discuss it.

Sang Oh Choi and his son, Jae, declined to comment through an attorney. James H. Simmons III, of Area Property, declined to discuss the state of the joint venture, but said his company remains “supportive of achieving the goals of the city, the council and the residents of the surrounding neighborhoods.”

Steven C. Boyle, managing director at Edens, called Sang Oh Choi an “incredibly hard worker” and a “true American success story.” Boyle said the joint venture with the Chois was formed earlier this year, and that both partners were eager to update a rezoning proposal that will include new retail in the mold of Union Market as well as apartments.

“It’s a view that we feel very aligned on,” Boyle said.

Boyle said he was aware that the Chois had been discussing their relationship with Area Property recently, but did not know specifics. With any luck, he said, Edens and the Chois will break ground on between 175 and 200 new apartments at the corner of Florida Avenue and Fourth Street later this year.

“Mr. Choi is excited to get something under construction,” Boyle said. “He’s been working at it a while now.”