PHILADELPHIA; PRINCETON, N.J. - Rohm and Haas Company and Chemical Specialties, Inc. (CSI), a wholly owned subsidiary of Rockwood Holdings, Inc., have signed an agreement to form a joint venture to serve the wood-treatment industry. The new company brings together the wood-biocides business of Rohm and Haas and the wood-protection chemicals business of CSI to provide an extensive range of advanced wood-treatment technologies and services to the global wood-treatment industry. The joint venture plans to commence operations this month. The transaction is subject to government review.