Capital croissance PME has invested $1.6 million in the acquisition of ACO Container Systems Ltd by Rotoplast Inc. Based in Pickering, Ontario, ACO is a maker of medium-sized and large plastic industrial storage tanks. The acquisition of the company by Rotoplast, an East Farnham, Québec-based rotational moulder, was closed last month. No financial terms were released. Capital croissance PME II is a private equity fund sponsored by Capital régional et coopératif Desjardins and the Caisse de dépôt et placement du Québec.