Hadrian Enterprise Park, which housed the town’s paint works before its closure in 2002, was put on the market in October 2015, at a guide price of £700,000.
The site, which once employed hundreds of people, failed to sell at auction.
But on Wednesday, a representative of site owners, Trans Britannia Properties, said discussions with a potential buyer were ongoing, and that more details should be forthcoming within the next two weeks.
The paint works opened half a century ago, originally as Smith and Walton.
It later became known as Crown Paints, and Akzo Nobel.
Hopes are high in Haltwhistle that a sale will bring much-needed investment to fulfill the potential of a site, which has been the subject of false hope over the past decade.
Plans to build a Story Centre on the site, depicting the history of Hadrian’s Wall, were shelved in 2007.
Two years later, a roundabout was built at a cost of £3.6m, providing access to the site from the A69 trunk road.
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