General Electric has struck a $252 million deal to sell the Seaport District property where it once planned to build a new Boston headquarters.

The company will sell the land along the Fort Point Channel, as well as the permit to build a 12-story building there, to Alexandria Real Estate Equities, a developer that specializes in life science and technology clusters. Two other companies, National Development and Charles River Realty, are also partners in the deal.

GE announced its intentions to sell the parcels in February, and agreed to use the proceeds to pay MassDevelopment, the state's economic development and finance agency, back for its $87 million investment in the site. The funding was part of the deal to bring the company to Boston. MassDevelopment will get an additional $11 million out of the sale.

GE will remain on the site as a tenant, however. The company signed a 12-year lease for two former Necco buildings where it plans to house its senior executive team and some 250 employees.

The company had originally promised to create 800 jobs at its Boston headquarters. But the historic conglomerate has struggled in recent years. GE has been scaling down operations, selling its oil and gas business, and spinning off a health care division.

GE CEO Larry Culp has been tamping down expectations, warning that 2019 is likely to be a difficult year for the company.

"This site offers a tremendous opportunity to continue to expand our presence in the top life science cluster in the world," Alexandria Real Estate Equities said in a statement about the acquisition, "and we are excited to have GE's headquarters on site."