STAMFORD — Taubman Centers, which co-owns Stamford Town Center, announced Monday that it had agreed to be sold to retail real estate giant Simon Property Group for about $3.6 billion, but the for-sale Stamford mall will remain on the market.

The announcement comes about five months after Bloomfield Hills, Mich.-based Taubman and co-owner UBS Realty Investors put the embattled downtown shopping center up for sale. The property could be redeveloped under a new owner, but the mall will remain open in the foreseeable future.

Stamford Town Center “is already for sale, and it is not anticipated that the announced transaction will affect that,” said Maria Mainville, Taubman’s director of strategic communications. “Further, Taubman, after the closing of the transaction, will remain an owner and the property manager of the shopping center.”

After the announcement, Taubman shares rocketed 53 percent Monday, closing at about $53. Simon shares saw a modest gain: They increased about 1.5 percent, to approximately $143.

Through the deal, Indianapolis-based Simon would acquire an 80 percent ownership interest in The Taubman Realty Group Limited Partnership (TRG), which owns 21 malls in the U.S., and three in Asia. Simon already owns or has an interest in 233 retail properties across North America, Europe and Asia. That list includes The Westchester mall in White Plains, N.Y., and two Connecticut sites: Clinton Crossing Premium Outlets in Clinton and Crystal Mall in Waterford.

“By joining together, we will enhance the ability of (Taubman) to invest in innovative retail environments that create exciting shopping and entertainment experiences for consumers, immersive opportunities for retailers and substantial new job prospects for local communities,” David Simon, Simon’s CEO, president and chairman, said in a statement.

Led by Chairman, President and CEO Robert Taubman, Taubman’s existing executive team would continue to manage the company’s properties.

“Over the last few years, David and I have developed an excellent personal relationship and importantly, Simon shares our commitment to serving retailers, shoppers and the communities in which we operate,” Robert Taubman said in a statement. “The board and I are confident that Simon is the ideal partner to help us build on our progress.”

Potential redevelopment

The for-sale portion of the mall covers approximately 515,000 square feet. Taubman and UBS would negotiate the price with the buyer.

A sale would include neither the 245,000-square-foot department store that Macy’s owns and operates at the north end of the mall nor the adjoining Bow Tie Cinemas Landmark 9 movie theater.

Macy’s plans to close about 125 stores during the next three years. That group does not include the Stamford location, according to Taubman officials.

At the same time, any redevelopment of the approximately 78,000-square-foot Saks Off 5th department store — located within the area that is for sale — would require an agreement with Saks.

To help attract buyers, the mall’s listing has noted that it is in an “opportunity zone,” an area whose new developments can qualify for a number of tax subsidies.

“The city will work with the new owner to develop a plan that will ensure the success of the site and integration into the streetscape of the downtown,” Thomas Madden, the city’s economic development director, said last year. “The current zoning allows the new owner to explore several different redevelopment options for the site. The key is how the redevelopment integrates into the surrounding downtown redevelopment.”

A sale would not necessarily lead to a wholesale transformation of the mall. A new owner could decide, for instance, to keep several existing sections including the restaurant plaza on Tresser Boulevard, which opened in 2007.

Any redevelopment could take years to plan, go through local and state government agencies’ reviews and then carry out.

Comings and goings

In the meantime, the mall is grappling with high turnover and a growing number of vacancies.

Among the latest departures, Apple is scheduled to shutter Wednesday the establishment it has operated at the mall since 2006. The technology giant is opening another store this week at the new SoNo Collection mall in Norwalk.

Stationery chain Papyrus and hosiery-and-shapewear seller Sasha are also closing, although their end dates have not been finalized.

Last month saw the departures of fast-fashion retailer H&M, shoe seller Clarks and casual clothier Uniqlo, adding to about a dozen closings in 2019. Like Apple, H&M and Clarks have decided to open stores at SoNo Collection.

About 20 vacant storefronts now pockmark Stamford Town Center, although the mall has attracted a number of newcomers in the past year. Arrivals in the past three months include a Fun Palace entertainment center; Kilim Design, a seller of Turkish rugs and houseware; and Luggage and Bags.

pschott@stamfordadvocate.com; 203-964-2236; twitter; @paulschott