GRTC is shopping for a buyer for its former headquarters in the Fan District — five years after the bus company moved to South Side.

Separately, City Council has agreed to provide $250,000 over two years to help get the old Blues Armory, the last piece of the failed Sixth Street Marketplace, back on the tax rolls.

Both properties are considered potential sites for multimillion-dollar development projects.

GRTC announced last Friday that it is seeking requests for proposals for the old administrative building and bus depot at Main and Davis streets.

The property has been vacant since 2010. GRTC has allowed murals to be painted on the buildings and hosted art events there in recent years. However, GRTC had to keep the property off the market during the cleanup of fuels and other hydrocarbon products that had seeped into the ground. GRTC expects to complete the cleanup by late fall.

The site had been used for public transit since 1903 — first for maintenance of electric trolleys and then for diesel buses. GRTC took over the site in 1973.

GRTC plans to accept proposals through July 8, with its board to choose the winning bid by Sept. 15, according to a schedule the transit company released.

Meanwhile, the old Blues Armory, which stands at 6th and Marshall streets near the Richmond Coliseum, has moldered since the closure of the marketplace seven years ago. It used to hold a food court, along with offices on its second and third floors.

Developers repeatedly have offered plans for use of the building. City Councilman Parker Agelasto, who pushed for the $250,000, said that plans couldn’t advance because the property’s deed is tangled up with a public-private company that no longer exists, Festival Diogenes.

City Attorney Allen L. Jackson plans to use the money to hire outside lawyers to handle the work of straightening out the deed so that the city can offer the building for redevelopment, possibly as a residential and retail complex. ­— JEREMY M. LAZARUS