The specialty chemicals Group Altana with headquarters in Wesel/Germany, has signed an agreement to acquire the global rheology business of Rockwood Holdings U.S. Inc.. The associated company section of the Rockwood business unit “Performance Additives“ is a provider of rheology additives with which the flow behavior of different materials can be optimized. With around 340 employees at four production sites in the U.S., UK and Germany, the rheology business achieved a turnover of 191 million US$ in 2012. After approval of the relevant antitrust authorities Altana will integrate the rheology business of Rockwood into BYK Additives & Instruments. The purchase price is 635 million US$. Completion of the transaction is expected in the 4th quarter of 2013.