Imagine you are shopping at a grocery store, and each department has different rules.

The meat department demands that you contribute a piece of art before buying a steak. In produce, you must sign a statement saying you will compost all your unused fruits and vegetables. On top of the varying regulations, store employees never know what is on their shelves.

You might avoid shopping there, right?

That's how it feels to try to buy a property from the City of Philadelphia and related agencies, one reason vacant parcels sit for decades. The city's new managing director, Richard Negrin, wants to change that to encourage development.

"What we're really talking about is creating some coordinated effort around how we identify, track, and dispose of government-owned properties," he said.

In Philadelphia, the Department of Public Property, the Redevelopment Authority, and the Philadelphia Housing Development Corp., a city-run affordable-housing developer, all own vacant land. So does the Philadelphia Housing Authority, a state agency funded with federal dollars.

That alphabet soup of agencies, along with speculators who allow properties to deteriorate while they wait for a neighborhood to rebound, contributes to blight, Negrin said.

"It's a frustration that has built up over many years and over many administrations," Negrin said Monday at Temple University during a conference on revitalizing urban neighborhoods organized by City Councilman Darrell L. Clarke.

Last week, Negrin pulled together representatives from all the different agencies to find ways to make it easier for people to buy publicly owned properties.

His effort won't be the first. The Street administration tried it. Mayor Nutter made the issue a campaign plank.

Agencies have made some progress. Both the Public Property Department and the Redevelopment Authority now list their properties for sale on websites.

But the problems remain huge. The city doesn't even know how many vacant parcels exist, let alone whether they are publicly or privately owned. Estimates range from 40,000 to 60,000.

Speakers at Clarke's conference agreed that one-stop shopping would lower development barriers.

Herbert Wetzel, City Council's housing director, brought along an aerial photo of the 1900 block of Turner Street, where three government agencies own properties.

The Public Property Department recently tried to sell one of those parcels, which could have destroyed a chance at comprehensive development, Wetzel said. The sale never happened, but Wetzel said the complications on the block highlight the need for the city to consolidate efforts.

"It can be a nightmare to develop a project where the land is owned by multiple public entities," Wetzel said. "It is costly. It is time-consuming, and in some cases the delays at one entity can jeopardize an entire project."

One idea the city is considering is a land bank, a governmental or quasi-governmental organization that assembles properties, especially those that are vacant, abandoned, and tax-delinquent, for productive use.

Other speakers emphasized the need to add attractive open space to make neighborhoods feel more welcoming. Penelope Giles, executive director of the Francisville Neighborhood Development Corp., said her organization had been able to hire people from the community to "clean and green" vacant lots. That puts people to work and helps them see their neighborhoods differently, she said.

"One of the questions I ask them is: What did you learn on this job? And often they say, 'I'll never throw trash on the street again.' "