Technology publishing firm CMP announced Wednesday that it has acquired Think Service Inc., operator of the Help Desk Institute, the world's largest membership association for information technology service professionals. Financial terms of the transaction were not disclosed. CMP said the acquisition broadens its services portfolio to include certification and training for IT support professionals. CMP said HDI will function as an independent operating unit within its International Customer Management Institute group, which is led by Ruthann Fisher, vice president and global brand director. Peggy Libbey, Think Service's president and chief operating officer, will continue to manage the operational direction of HDI, CMP said. Think Service is headquartered in Colorado Springs, Colo. CMP is based in Manhasset, N.Y.