Having received no offers for a takeover, the organization that occupies the Prince Music Theater on Friday terminated its lease with the owners of the building on Chestnut Street just west of Broad Street.

American Music Theater Festival, founded in 1984, also intends to dissolve. The future of the building is uncertain.

"It's a significant loss if it goes away. If it becomes a drugstore, it would be horrible for the city," said J. Andrew Greenblatt, executive director of the Philadelphia Film Society, one of the theater's most frequent users.

The Prince lost its leadership in May with the death of its board chairman, the philanthropist Herb Lotman. In July it announced it was seeking another organization to take over and continue the building's use as a theater.

"We gave it five or six months after Herb's death, but at some point you have to say, if nobody is willing to step in, we can't do it any longer," said Stan Fronczkowski, a longtime colleague of Lotman's who is working with his widow, Karen, and son, Jeff, on the matter. "What we were looking for was someone to step up not only operationally but also financially. The board does not want to continue in a leadership role anymore."

Winding down the business could take until the end of the year, he said. Performances are slated in the theater through Nov. 30.

Fronczkowski said the festival organization had received three serious expressions of interest - two from New York theater companies and one from an individual - but none evolved into a commitment. He said he believed the building's owners - a partnership that includes Philadelphia real estate owner/developers Ira M. Lubert and Ron Caplan - would be open to a new group continuing to operate the building as a theater. "But if no one steps forward, then they have to decide to do something else with it," he said.

Several of the building's owners and their representatives either did not return phone calls, or could not provide information about plans for the building.

The theater has seven full-time employees and 15 to 20 who are brought in on a show-to-show basis, he said.

The Prince opened in 1921 as the Karlton Theater, became the Midtown Theater in 1950, and was long ago stripped of its original exterior and interior detail. The building was bought by the American Music Theater Festival in 1999 and renamed for the Broadway producer-director Harold Prince, but the group, led by cofounder Marjorie Samoff, had difficulty meeting mortgage payments, and filed for bankruptcy in 2010. After the current owners won the building at bankruptcy auction, the organization effectively split into two - the building owners and the arts group, with some overlap.

In its new guise - the 2013-14 season was its first - the Prince no longer produced its own shows, although Lotman had hoped to resume producing. Rather, it imported concerts and other shows, and leased itself as a rental facility to local groups.

The Curtis Institute of Music, which began mounting opera productions there in 1999, must now find a stage for its May production. "We're trying to figure it out, and most of the logical venues are booked," said Curtis executive vice president Elizabeth Warshawer.

Philadelphia Film Society's Greenblatt said that for his organization, no longer having the Prince would be "really, really horrible. The Prince is a unique venue in its size, with a capacity of 460, and the fact that it is nonunion makes it reasonable to rent. It has that great big lobby and the black box for receptions. It's a big problem for us, and we haven't quite figured out how we are going to run a festival without it."

Although only about 15 percent of Philadelphia Film Festival's screening are held at the Prince, those screenings, since they are the highest-profile ones, account for about 30 percent of the festival's attendance, said Greenblatt.

After the Prince issued its call for a takeover this summer, Mayor Nutter met with Prince officials and expressed a desire for the building to continue as a theater, said Fronczkowski. But he has not heard from the Nutter administration since. "They said they would try to be helpful, and that was where we left it," he said.

Asked whether the administration is still involved, a Nutter spokesman Tuesday did not provide an answer.