AT&T announced that it has agreed, through one of its subsidiaries, to acquire privately held Interwise, a leading global provider of voice, Web and video conferencing services to businesses. AT&T will pay approximately $121 million in cash for the company.

The transaction, which is expected to close in the fourth quarter, strategically aligns Interwise’s innovative IP-based conferencing and collaboration solution with AT&T’s enterprise networking, communications and collaboration services, global MPLS-based IP network and its industry-leading conferencing portfolio of services.

Following the acquisition, the company will operate as a business unit within AT&T Global Business Services, which serves the largest enterprises around the world and is led by Group President Ronald E. Spears. AT&T expects to retain Interwise’s management team and its domestic and international operations, including its R&D center in Israel.