An open house was held Wednesday morning at the shuttered General Motors Willow Run Powertrain plant to showcase former GM properties for sale across the country, including the sprawling Ypsilanti Township factory.

The event, which targeted potential buyers, was held by the Revitalizing Auto Communities Environmental Response (RACER) Trust.

RACER was established in March 2011 by the U.S. Bankruptcy court to clean, revitalize, and eventually sell General Motors locations that were closed when the company declared bankruptcy in 2009. The event showcased both the properties and the partnerships the organization has fostered with local communities, government agencies, and prospective buyers.

RACER has made 17 sales thus far and expects to sell another two dozen properties in the coming year. However, according to Mathy Stanislaus, an assistant administrator at the Environmental Protection Agency, some sites may take longer to complete the clean-up and redevelopment process.

"Some lend themselves to short term development, while others require more long term planning," he said. "The challenge is prioritizing among these properties."

The Willow Run plant was one of the largest plants to close and be put under RACER's management. The plant had been in operation since World War II when it produced one B-24 bomber per hour, the fastest rate in the country. GM took over the plant in 1953, and it produced over 82 million auto transmissions before closing in 2009.

Bruce Rasher, a RACER trustee, said that RACER is working within the regional "Aerotropolis" framework in developing a plan for the closed plant. The Aerotropolis idea is to bring global supply chains through the region, utilizing the Detroit Metropolitan Airport and the Willow Run Airport, which abets the closed plant.

They have teamed with the Wayne County Edge, Ann Arbor SPARK, the Michigan Economic Development Corporation, Ypsilanti Township, Washtenaw county, and other organizations to market the property to prospective buyers.

"Our working idea is that the parts of the plant adjacent to the the airport would go toward aerospace companies," Rasher said.

"The parts of the plant closer to the rail and highway we are focusing more on general manufacturing and logistics users."

He added that and RACER has received interested from American aerospace companies and some Canadian companies who want to work with US Department of Defense contracts but need to do their manufacturing in America.

"RACER has a unique set of advantages and challenges as property managers," Rasher said.

"We have good relationships with both local communities and regulatory agencies that help us be more attractive to potential buyers. However, because we have the mandate for broad economic development and clean-up of sites, we demand more from our buyers than they are used to."

According to Rasher, In addition to talking about purchase price, RACER also requires the purchaser explain the plan for redevelopment or new development, how they plan to create jobs in the community, and they must investigate how the redevelopment would or would not interfere with the Trust's environmental cleanup.

These additional requirements can be hard for buyers who are not used to them, but RACER maintains that they are good for the long term health of the community.

Ben Freed covers business for AnnArbor.com. Reach him at 734-623-2528 or email him at benfreed@annarbor.com. Follow him on twitter @BFreedinA2