A Malden development company that built the Legal Sea Foods quality control center in South Boston’s marine industrial park is moving ahead with a 283,689-square-foot development on a vacant 6.5-acre portion of the Massport Marine Terminal site.

Pilot Development Partners says the project will help prop up the working port area and generate up to 150 permanent jobs in Boston’s maritime industry.

Plans call for a 48,000-square-foot seafood and distribution plant for Boston Sword & Tuna on one of three subparcels that Pilot leases from Massport, owner of the 29-acre marine terminal property on Fid Kennedy Avenue. Boston Sword & Tuna, which has approximately 100 employees, plans to relocate from a 30,000-square-foot plant at 8 Seafood Way and will double its production at the new building.

A second site would be developed with a 101,300-square-foot building including 280 parking spaces on three levels, a union hall for the International Longshoremen’s Assoc. and a retail seafood market. Pilot is in discussions with companies for a third building totaling 62,000 square feet, according to documents submitted to the Boston Planning and Development Agency.

Massport picked Pilot to develop the parcels following a request for proposals in 2016.