The Philadelphia 76ers have decided not to build a $1.3 billion downtown arena, a surprising move that comes just weeks after the team received approval for the controversial project from the city council.

The ownership groups of the Philadelphia 76ers and Flyers announced plans to build a new arena in South Philadelphia that would open in 2031.

Plans to build an arena for the Sixers in Center City have fallen through, and the team plans to stay in South Philadelphia, sources close to the negotiations say.

The stunning reversal comes as a relief to critics of the plan to put a $1.3 billion arena near City Hall at the edge of Chinatown. Mayor Cherelle Parker on Monday called the proposal “a win, win, win,

It is a head-spin development from the fight the 76ers have lodged over the last two years when it sought to build a new arena in Chinatown and close to the city’s center, and as it went to battle with Comcast,

The Philadelphia city council voted on Dec. 19 to approve the downtown arena after more than two years of heated debate over the 76 Place proposal.