Allianz S.E. has appointed Oliver Bäte to succeed Michael Diekmann as CEO of the German insurer, effective May 7, 2015, the company said in a statement Thursday.

Mr. Bate will continue to be responsible for global property and casualty until the company's annual general meeting May 6, 2015. His contract runs through Sept. 30, 2019, according to the statement.

The company's supervisory board appointed Sergio Balbinot to the board of management of Allianz S.E. for four years beginning Jan. 1, 2015, with responsibility for the insurance business in western and southern Europe, including France, Benelux, Italy, Greece and Turkey.

Axel Theis, CEO of Allianz Global Corporate and Specialty S.E., has also been appointed by the supervisory board for four years, in charge of the global industrial insurance business, credit insurance and the insurance business in Ireland and Great Britain and, beginning May 7, he will also take over global property and casualty from Mr. Bäte, the statement said. He succeeds Clement Booth, who is retiring.

Others had their appointments to the management board extended, including Manuel Bauer, until the end of 2015; Dieter Wemmer and Werner Zedelius for three years; and Helga Jung for five years. Beginning in 2015 Mr. Bauer will become responsible for the insurance business in Australia while Jay Ralph will take over responsibility for the insurance business in the U.S.

“Allianz owes gratitude to Gary Bhojwani, Clement Booth and, particularly, Michael Diekmann,” Helmut Perlet, chairman of the supervisory board of Allianz, said in the statement.

Chris Fischer Hirs, chief operating officer of Allianz Global Corporate and Specialty S.E., will succeed Mr. Theis as CEO, said a separate statement from the company.

The company also said that Nina Klingspor will join its board next January as chief financial officer from her previous role as head of CEO Office at Allianz S.E. since 2012.

“While I'm looking forward to continuing to be closely involved with the company in my new role, I know that I leave AGCS in Chris's expert hands,” Mr. Theis said in the statement.