In this Nov. 5 photo, Mayor-elect Muriel Bowser speaks to reporters during a news conference at the National Press Club in Washington. (Manuel Balce Ceneta/AP)

The District’s mayor-elect said Tuesday that she would move to “de-link” the sale of a valuable city property from a broader deal to build a stadium for the D.C. United soccer franchise, a move that could ease political concerns but create new complications for the $300 million proposal.

Muriel E. Bowser, who holds a key position as both the city’s next chief executive and as chairman of the D.C. Council’s Economic Development Committee, announced her intentions Tuesday to a gathering of the Federal City Council, an influential group of civic leaders.

“I support building a soccer stadium in the District of Columbia, and, more than that, I support spending public dollars to get it done,” Bowser told the group, saying the project would create jobs and benefit local businesses. But, she added, she was trained on finding a “deal that’s fair” that reduces the city’s risk and protects taxpayers.

Bowser made clear that she would nix the transaction at the deal’s core, which would sell the Frank D. Reeves Center, a hulking 30-year-old city office building, to the Akridge real estate firm in return for cash and land on the proposed stadium site, at Buzzard Point in Southwest Washington.

“When we do that, we will be able to focus our resources and attention on the Southwest site,” she said. “We will preserve the opportunity to build affordable housing at the Reeves Center site, and we will be able to ensure we have a feasible way forward on a new Reeves Center east of the Anacostia.”

Bowser, who assumes the mayoralty on Jan. 2, told the crowd of more than 100 business and civic leaders that she wants the deal to be through the council before year’s end. “I don’t think anybody wants to restart this conversation in January, do we?” the Ward 4 Democrat said.

Bowser’s council committee has tentatively scheduled a markup of the soccer legislation for Friday, although that meeting could be delayed until next week. For the stadium legislation to pass before the end of the council period, the council must take the first of two votes at its Dec. 2 meeting.

Among those in the audience were City Administrator Allen Y. Lew, who negotiated the present stadium deal on behalf of outgoing Mayor Vincent C. Gray (D), and D.C. Council Chairman Phil Mendelson (D), who has questioned the wisdom of including the Reeves Center sale in the stadium deal.

After Bowser’s remarks, Lew said he would continue discussions with Bowser, Gray and other parties involved in the talks. He acknowledged that changes to the city budget passed this year undermined the original rationale for the Reeves Center swap by opening up new space underneath the city’s borrowing cap. “It’s really up to the new mayor as to how to use it,” he said.

Bowser said she will work with Mark H. Tuohey, a lawyer who helped arrange the deal that came together nearly a decade ago to build a Major League Baseball stadium in the city, to reassemble the D.C. United deal without the Reeves swap. The team has pledged to build the actual stadium, for a little more than half the project’s total cost.

The major outstanding question is how Akridge will react to the unraveling of a deal that it has painstakingly negotiated with the Gray administration for more than two years.

The chance to redevelop the Reeves Center site, at 14th and U streets NW, has been seen as a prime opportunity in a hot residential market. But the prospect of trading the property without an open auction has generated concerns among council members and some outside observers who have questioned the accuracy of the real-estate appraisals underpinning the deal. And the building’s neighbors have expressed worry about its potential replacement.

Bowser called firm chairman John E. “Chip” Akridge III on Friday to share her misgivings about the deal as structured, said two people familiar with the conversation who spoke on the condition of anonymity because they were not authorized to speak publicly about it.

Akridge President Matthew J. Klein said Tuesday evening it was disappointing to see Bowser attempt to change the arrangement this late in the process. “We have a deal in place,” he said. “It’s a fair, open and transparent deal, and it’s been vetted more than maybe any deal I’ve ever seen in the District of Columbia.”

Klein said he had not considered what his company might be willing to accept in place of the Reeves Center.

While Bowser said she would move to abandon the Reeves Center swap with Akridge, she said a land swap involving Pepco could proceed. That trade would give the city the site of a former electrical substation at the stadium site in return for a parcel in the NoMa area that Pepco has eyed for new infrastructure.

The best news appeared to be for D.C. United, whose majority owner is Indonesian media magnate Erick Thohir. Although there is risk for the team in the possibility that Akridge could walk away from the deal, it won an unqualified public commitment from the city’s incoming mayor.

“If we’re going to be a world-class capital, it’s important that we maintain the world’s sport, soccer, right here in the District of Columbia,” she said.