Summary Box: Lonza paying $1.2B for Arch Chemicals

    THE DEAL: Lonza Group Ltd. of Switzerland said Monday it agreed to buy Arch Chemicals Inc. for $1.2 billion, or $47.20 per share. Arch Chemicals makes antimicrobial products used in personal care, water treatment, and industrial applications, and Lonza said the deal will make it one of the leaders in that market.

    THE PRICE: Lonza is offering a 36.7-percent premium to the average closing price of Arch Chemicals shares over the last 30 days. Shares of the Norwalk, Conn., company jumped 11 percent Monday.

    THE OPPORTUNITY: Lonza said the global market for antimicrobial products is worth $10 billion a year.