Lonza said it will acquire U.S. biocide producer Arch Chemicals for about $1.2 billion. The cash offer is subject to customary conditions including the tendering of more than two-thirds of Arch Chemicals' outstanding shares of common stock and clearance from antitrust regulatory authorities. Lonza said it expects to begin the tender offer by July 15 and to complete the tender offer later in 2011.

Lonza CEO Stefan Borgas said the acquisition is an "excellent strategic fit" for the Swiss-based fine chemicals and contract manufacturing company.  The takeover will put the company at the forefront of the microbial control business, with 2010 pro-forma sales in the market of about $1.6 billion, combining the complementary product solutions of both companies.

The global microbial control market is currently valued at approximately $10 billion, and is growing at approximately 4-6% per year. The key end-use segments of the market -water treatment, hygiene, materials protection and personal care - are growing at faster rates. The largest markets are North America, Europe and Japan. The fastest growing microbial control markets are Brazil, India, China and South Africa.