Arco retained Salomon Bros. to sell three units.

The three small agricultural units were earmarked for divestiture in a major restructuring announced last year. The three units are Arco Seed Co. and Valley Dehydrating Co., both of El Centro, Calif., and the Plant Cell Research Institute of Dublin, Calif. Arco Seed, with about 220 workers, develops and markets vegetable seeds. Valley Dehydrating, with 62 employees, runs a leaf-protein concentrate plant. The Plant Cell Research Institute, with a staff of 85, is a research center.