The Market East corridor shelters plenty of concrete mutts, but the parking garage at Seventh Street may be the ugliest dog in the pet shop.

Streaks of rust and pigeon poop mark the five-story hulk, built back in 1966. Its looming presence crowds the Colonial brick of the Graff House and the distinguished gray block of the Philadelphia History Museum. It offers no lure to sore-footed tourists seeking escape from the crush at the nearby Liberty Bell.

To fix Market East, the haggard eight-block stretch between Independence Mall and City Hall, experts say it's crucial to fix this site. Now, with the recent $17 million sale of the garage to Brandywine Realty Trust, change may be in motion.

The Radnor company is no ordinary buyer. Its urban vision has been transforming the University City area since it built the Cira Centre a decade ago. The firm continues to be integral to the makeover of waterfront property near the University of Pennsylvania, where new skyscrapers rise.

Brandywine has not disclosed specifics of its plans for the property - efforts to contact CEO Jerry Sweeney were unsuccessful - but it's clearly focused on the surge of development on Market East, from the makeover of the Gallery mall to the construction of a big retail and apartment complex closer to City Hall.

The 330-space garage, Sweeney recently told stock analysts, is "a future development site, pending the continued emergence of the Market East corridor."

During what Sweeney described as a transitional period, Brandywine intends to run a better and more lucrative garage.

"This asset sits right at the key intersection," Sweeney said. "We know we have the zoning in place, so we'll be very opportunistic both in terms of timing of what we want to do there as well as its ultimate use."

Brandywine's purchase has been overshadowed by the news surrounding the planned $325 million remake of the Gallery.

Last week City Council considered bills to approve a top-to-bottom renovation of the mall, long a deadening force on Market. Council delayed action over concerns about mall-worker wages and kiosk owners, but could vote by mid-June.

The parking garage, though, is no bit player in the future of the once-bustling corridor, said former city Commerce Director James Cuorato.

"This to me is a major, major development that seems, so far, to be under the radar," said Cuorato, who is CEO of the nearby Independence Visitor Center, chair of the Philadelphia Redevelopment Authority and a former Brandywine executive.

"It's in a key location, between the historic district and the Convention Center. Second, it's not the most attractive building in that stretch by any means. Most significant, you have a top-of-the-line, first-class developer, who is committed to Philadelphia, making a decision to invest in this area."

One factor that could hasten Brandywine's development plans is the zoning. The site is tagged for mixed-use development, coveted by developers because it can allow high-rises, housing and shops.

Brandywine bought the garage from New York developer Richard Basciano, infamous as owner of the Center City building that collapsed onto a Salvation Army Thrift Store, killing seven people in 2013.

A representative for Basciano did not return a call seeking comment about the sale.

The garage covers a half-block, dominating the southeast corner of Seventh and Market and overhanging over the sidewalk. Its street-level stores on Market include Dunkin' Donuts, Jerry Blavat's Geator Gold Radio Network, Shirt Corner and Yu Yu nails.

The Honey Restaurant has left. So has the palm reader, Readings by Theresa (who doubtless knew in advance that it was time to go).

People who have spoken with Brandywine leaders expect the mix of stores to change quickly, moving more in line with a vision of a new, revived Market East. They speculate that the garage itself will stay or go based on the pace of Market East revival.

Across the street from the garage stands the Graff House, also known as the Declaration House, a reconstruction of the home where Thomas Jefferson drafted the Declaration of Independence. Next to that is the Independence branch of the Free Library, and directly behind the garage is the Philadelphia History Museum.

"I want more visitors, not more parking," said museum CEO Charles Croce. "Even the hint that the retail would be upgraded would be to our benefit."

To a smaller institution such as the museum, setting and foot traffic matter, he said. A more attractive neighbor can boost the fortunes of the block and the corridor.

"It's good news all around - the signature first move on that block," said Harris Steinberg, who studies development as executive director of the Lindy Institute for Urban Innovation at Drexel University. "It says we may be getting the magnets at the ends of Market to fill in the middle."

Ideally, Harris said, the garage would be replaced with something intriguing, a project that can draw tourists from Independence Mall onto a newly welcoming Market Street for dinner, drinks and entertainment.

"Brandywine makes careful, well-thought-out decisions," said Cuorato, the Visitor Center CEO. "The fact they chose to invest in the Market East area is very significant. . . . Things are starting to move."