The recent sale of Nalco by Suez SA for $4.35 billion has added another chapter in the history of water treatment markets. Mergers and acquisitions and consolidation in this market have given rise to two companies as the top players: GE Betz and Nalco, which have evolved as 'one stop shopping' entities in water treatment and attractive investment targets. Nalco had sales of about $2.7 billion in 2002.