Hoping to head off a possible demolition threat to the Boyd Theater, the Preservation Alliance has asked the Philadelphia Historical Commission to declare the Chestnut Street movie palace a protected landmark.

Alliance director John Gallery said yesterday that he had nominated the art deco theater for historic designation Wednesday after receiving assurances that the Nutter administration would support the action. The application is scheduled for a July 16 hearing before the commission's designation committee.

In a statement yesterday after the nomination became public, Mayor Nutter urged the Historical Commission to give the application "its fullest consideration."

"I pledge to work with [the commission] to preserve this building," Nutter added.

His statement came a little more than a week after the National Trust for Historic Preservation thrust the theater into the spotlight. The group included the ornate movie house on this year's list of America's 11 most endangered historic sites after learning that the owner, Live Nation, had abandoned restoration plans and put the Boyd up for sale.

Concern about the Boyd, which is on the 1900 block of Chestnut and is the only surviving movie palace in Center City, has been mounting since Live Nation decided to get out of the theater business. This month, the entertainment company announced that interested buyers had until Wednesday to bid on the theater, known in its final years as the Sameric. Live Nation has not revealed anything about the submissions.

There is no guarantee that the Historical Commission will approve the Preservation Alliance's request, but the application was partly a tactical maneuver. Building owners cannot seek a city demolition permit as long as a nomination for historic designation is pending.

"It gives the Boyd interim protection," Gallery said.

He acknowledged that the alliance "had some concerns about whether the nomination was the right thing to do in terms of working cooperatively with Live Nation." But ultimately the nonprofit advocacy group decided it needed to protect the Boyd from the unknown.

The alliance failed twice before to win landmark status for the Boyd. After its 2002 nomination was rejected, then-owner Ken Goldenberg went straight from the hearing to the city's Building Department to file for a demolition permit. As long as a demolition permit is active, structures cannot be nominated for historic status.

Howard Haas, who founded Friends of the Boyd to promote the theater's restoration, said the movie house should have received historic certification years ago, long before it stopped showing movies in 2002.

"It has a beautiful art deco exterior with many original decorative elements intact. It's about time it was recognized as a landmark," Haas argued.

But the alliance, which has extensive experience crafting historic-designation applications, became entangled in a legal morass when it previously tried to win such status for the Boyd.

The theater's most impressive architectural elements are inside the lobby and auditorium rather than on the facade. Because Philadelphia's preservation laws do not cover interiors, the courts struck down the alliance's original 1987 nomination. The Historical Commission rejected the 2002 attempt on other grounds.

This time, Gallery said, the alliance rewrote the application to make sure its arguments strictly comply with Philadelphia's preservation laws. Though a building's fine interiors cannot be listed as the basis for landmark status, its role in important events may be considered.

Among the important events listed in the new application is the 1993 state Supreme Court ruling overturning the Boyd's original designation. That decision was itself a landmark and caused many cities to revamp their laws.

"Every preservation student in the country is taught about that lawsuit," Historical Commission director Jon Farnham said.

Contact architecture critic Inga Saffron at 215-854-2213 or isaffron@phillynews.com.