Elbit Systems' Joseph (Yossi) Ackerman is stepping down as CEO of the defense electronics company next April, after 16 years at the helm.

Ackerman, 63, who oversaw 30 acquisitions during his presidency to make Elbit Israel's biggest nongovernment defense company, will be replaced by Bezhalel Machlis, 49, currently an executive vice president and general manager of the company's land and C4I Division.

Ackerman joined Elbit in 1982 as a manager in the aborted Lavi jet fighter project and filled various positions inside the company until being promoted to CEO in 1996. Among his tasks was to oversee Elbit's first overseas purchase, the U.S. company EFW, which he then managed for Elbit.

EFW was a milestone development for Elbit, enabling it to bid on U.S. defense contracts for the first time by giving it a domestic presence in the United States.

Over Ackerman's years as CEO, Elbit's revenues grew from $400 million to $2.9 billion in the last 12-month period, while boosting its market capitalization to $1.4 billion. Nevertheless, the company is far from the peak of its stock market performance. Its share price has dropped 45% since August 2009 as defense budgets in the U.S. and the West have been contained by weak economies as well as by the chill in Israel's relations with Turkey, once a major Elbit customer.

Ackerman is retiring at a relatively young age. The company explained the move as a way of refreshing management of an unusually long tenure.