The sprawling former IBM Corp. plant here, known as TechCity since 1998 when it was bought by a developer, is for sale again.

Alan Ginsberg, who bought the site and has worked on developing it as a business center, announced today, Wednesday, that he has hired a company to find a buyer for all or part of it.

Ginsberg hired Alvarez & Marsal Real Estate Advisory Services, or A&M, “to begin a process that will result in the sale of all or part of the 258-acre property,” a spokesman said. The site has 1.7 million square feet of existing space “and has the potential for millions of square feet of additional development.”

Ginsberg said in his announcement, “We have seen some notable achievements since we took ownership in 1998. We have attracted a number of businesses, obtained approval for a new master plan and, through our marketing, told a positive story about the region to countless people around the world.”

He added, “I am also pleased to be able to say that the completion of IBM’s environmental remediation efforts is now within sight – perhaps less than a year away.”

IBM has continuing responsibility for chemical contamination at the site.

Ginsberg, whose activities in realty had been largely in the New York City metropolitan area, came to Ulster County seeking IBM’s surplus property and seeing it as a multi-tenant high-tech site. There have been some successes, including some more traditional forms of manufacturing or business use.

“Having devoted a significant portion of my life and a considerable amount of my personal resources to making TechCity a success, I am now hopeful that it will attract the interest of developers who see it as an asset with great potential,” he said.

As many as 7,000 IBMers worked at the plant in its heyday.