Teva Pharmaceutical Industries said on Monday William Marth will resign as head of Teva Americas Generics, part of a leadership shake-up that named Allan Oberman the unit's CEO.

Oberman moves up from his role as senior vice president of North America Generic Pharmaceuticals.

Since taking over as CEO of Teva Pharmaceutical Industries in May, Jeremy Levin has quickly shuffled senior management. In making the changes, he has revealed his view of the company's weaknesses.

The Israeli generic drug maker described the changes as "an orderly management succession" in which Marth will leave immediately but serve as a senior adviser to Levin until he retires at the end of 2013.

"These changes are part of our ongoing process to build a premier leadership team and reshape Teva," Levin said in a statement.

Oberman will report directly to Levin and have responsibility for the company's Latin American businesses.

The company also announced the appointment of Jill DeSimone to the newly created position of senior vice president and general manager of Teva Global Women's Health.

Shares of teva fell 0.8% in Nasdaq trading yesterday to close at $41.14.