ROCKLAND, Maine — One of the midcoast’s largest manufacturing plants is expected to be sold by next June. That includes the Rockland plant off Tillson Avenue where carrageenan is produced from seaweed. The plant is the top property taxpayer in Rockland with total taxable property at $23.2 million and paid $383,000 in taxes. The state reimburses Rockland for slightly more than half of that loss of revenue from the exempt personal property. “We are delighted to welcome IFF’s Food Ingredients business to CVC’s U.S. portfolio,” said Lorne Somerville, managing partner and co-head of North American private equity at CVC.