A subsidiary of The Washington Post Co. plans to sell two shipping terminals in Old Town Alexandria that city officials consider key to the redevelopment of the waterfront.

The warehouses, nearly half a mile apart along the Potomac River, served for decades as receiving locations for pulp and newsprint. Today, Robinson Terminal Warehouse Corp., a wholly owned subsidiary of The Post Co., uses the 600,000 square feet largely for storage.

“We have decided that the time is right to market the North and South Terminals on the Alexandria waterfront, where we have had a long history of operations,” Robert W. Taylor, Robinson Terminal president, said in a statement in a statement.

He added that the company plans to consolidate operations in Springfield, where The Post’s printing presses are located.

More than seven decades after they opened, the warehouses sit amid a patchwork of parks, low-rise office buildings, townhouses, shops and restaurants, remnants of an industrial era that existed before the waterfront evolved into a popular tourist destination and upscale neighborhood.

City officials, looking to further attract tourist business and expand Alexandria’s commercial tax base, consider the sites’ redevelopment critical to fulfilling a new vision for the area.

Alexandria Mayor William Euille (D), who won reelection in November based in part on his leadership in redeveloping the riverfront, said The Post Co.’s decision to sell the warehouses “removes a potential stumbling block.”

“I think this is a positive thing because it removes any concern about whether The Washington Post will be a participant or player in the waterfront,” Euille said. “They’re simply saying they’re cashing out, they’re walking away. Hopefully new owners . . . will embrace the waterfront concept and participate in the future of Alexandria.”

Since news of the possible sale of the headquarters became public, some historic preservationists said they consider the building architecturally significant and may work to protect it.

The warehouses have taken center stage in a heated local disagreement over the waterfront, with some residents charging that commercial redevelopment of the properties poses a threat to the riverfront’s tranquility and the public’s needs.

A new land-use plan, which passed the Alexandria City Council just over a year ago, allowed for two new hotels, with no more than 150 rooms each, to be built or redeveloped along the eight-block-long area in Old Town. Another developer is working on a proposal to build one boutique hotel on separate property.

Controversy over the waterfront plan has boiled over into the courts. Robinson Terminal sued the city in 2008 over zoning changes that it said could harm the terminals’ value. That lawsuit was resolved, but another suit challenges the area’s new waterfront plan. The Virginia Supreme Court is expected to hear that case by early March.

Whoever buys the properties would be allowed to build up to 50 feet high on the south terminal site, according to Faroll Hamer, director of planning and zoning for Alexandria. The north terminal, bisected by Union Street, would have a 66-foot height limit on the western portion and a 30- to 35-foot limit on the eastern section. The city is requiring public access along the water, where both terminals now block strollers, bicyclists and passersby.

“We want people to walk there, we want it to be public, maybe retail or other public use,” Hamer said. “The piers will be public.”

Neighbors still have concerns.

“I think there is still a question of how the sites will be redeveloped,” said Bert Ely, co-chairman of Friends of the Alexandria Waterfront. “We’ve always known and acknowledged something was going to happen there. The question is what. Open space is a form of redevelopment. We would still hope what happens on those two sites will be additive to the waterfront and not detrimental to Old Town.”

The Post Co. announced the planned sale four days after saying it would consider selling its downtown headquarters and that it had hired real estate consultants including Studley Inc., which will handle the warehouse sales.

Commercial real estate brokers said the properties are likely to attract developers interested in building high-end housing or luxury hotels. The city assesses the combined value of Robinson Terminal North and South at about $30 million.

Jayne Shister, senior managing director at Cassidy Turley, said she expects condominium or apartment builders to be the most aggressive suitors. “It’s on the water, on a park, within walking distance to King Street,” she said.