CONVENT, La. (AP) — Nucor Corp. says it will begin construction immediately on the first phase of its iron and steelmaking project in St. James Parish.

Charlotte, N.C.-based Nucor says the way was cleared by the issuance of an air quality permit Thursday by the Louisiana Department of Environmental Quality. The permit covers two iron-making plants. Nucor initially plans to build one plant with plans to expand.

The plant is part of what could eventually be a $3.4 billion complex employing up to 1,250 people. The first phase calls for 150 permanent jobs.

The plant will use a technology that converts natural gas and iron ore pellets into iron used by Nucor’s steel mills. If the full project is built, it will include a coke plant, blast furnace, pellet plant and steel mill.