CLAYTON — Some of the most valuable real estate in the region should be hitting the market soon after years of sitting unused under the ownership of the St. Louis County Port Authority.

By the end of the month, the new leaders of the Port Authority plan to issue requests for proposals for three downtown Clayton properties that could be worth a combined $25 million, according to value estimates from the St. Louis County Assessor’s office.

Their sale could net a big payday for the county, which has had to navigate tight budgets in recent years. And it could finally put two vacant buildings and an empty lot in otherwise booming downtown Clayton into productive use, generating tax revenue and foot traffic.

The Port Authority is in the process of conducting new appraisals of the properties and hopes to release a request for proposals in weeks. Responses would be due 45 days after that, Port Authority attorney Andrew Ruben told a St. Louis County Council committee Tuesday.

Potential buyers have been inquiring about the property and the real estate market is strong.

“We are ready to move forward aggressively,” Ruben said.

The properties include the former family courts building — empty except for the occasional police tactical team that practices maneuvers there — at 501 South Brentwood Boulevard. It’s adjacent to Enterprise Holdings’ headquarters, and that company has said it has been interested in the property for years.

Also hitting the market will be 21 South Meramec Avenue, the former headquarters for Seven-Up and most recently used for county offices. Empty since 2012, the structure is in bad shape and many think it will likely make sense to raze it for new development.

Adjacent to that 10-story building is a vacant lot that once housed the county health department. Officials believe potential developers will likely want to combine the site with the Seven-Up building site.

Off the table, for now, is the county-owned parking lot on Central Avenue across from the government center. It could be part of a future plan to build new county offices to replace the Lawrence K. Roos government building.

Voters passed a bond issue in 2012 to finance a new family courts building next to the main courthouse in downtown Clayton, putting the reshuffling of county-owned real estate in motion.

In late 2016, the administration of former St. Louis County Executive Steve Stenger finally transferred the properties to the Port Authority. But the administration and the Port Authority were mum on plans for the sites.

St. Louis County Councilman Mark Harder, who led the Tuesday meeting, said he and council members had asked for updates on the Clayton properties for years when the Port Authority was led by Stenger ally Sheila Sweeney.

“Every November she would give us some reason why they weren’t selling them,” Harder said.

The County Council passed an ordinance last week taking back ownership of the properties while the Port Authority finds buyers. The Port Authority can’t sell them for less than 95% of the new appraised value without authorization from the council.

Less clear was the timeline for finding a buyer for Jamestown Mall in north St. Louis County, another Port Authority-owned property. Unlike the Clayton properties, where the goal is to sell them for the highest price possible, the North County property might carry a higher consideration for jobs and community services, officials said.

Last year, Kansas City-based NorthPoint Development proposed a plan to redevelop the site as a logistics park. But it officially withdrew the offer after the Port Authority indicated it wanted to go through a new RFP process. When that request might be issued is not yet clear.

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