NATION

International Business Machines on Tuesday elected Kaspar V. Cassani and Jack D. Kuehler executive vice presidents.

It said Cassani, 58, would take over most of the responsibilities of Vice Chairman Paul J. Rizzo, 59, who is retiring after 29 years at the computer giant to become dean of the University of North Carolina’s School of Business Administration. His retirement is effective Aug. 31.

Rizzo was required to step down as vice chairman under an IBM policy that says certain positions must be relinquished at age 60.