Cabot Microelectronics ( CCMP), a supplier of goods to semiconductor makers, said Wednesday it agreed to buy a number of patents from IBM ( IBM) that cover chemical mechanical-planarization slurry technology. The financial terms of the agreement weren't disclosed. "For almost 20 years, since the early days of CMP technology, we have had a productive and collaborative relationship with IBM as an important customer, and we believe that this acquisition of CMP slurry patents reflects and furthers this positive relationship and our ability to bring value to all of our customers," Cabot said. Shares of Cabot were down 76 cents, or 2.5%, to $29.35. IBM was slipping 3 cents to $77.99.