Tom Godlasky, who was the CEO of AmerUs Group Co. when that Des Moines-based company was bought by Aviva plc, will retire from his position as head of Aviva’s North American operations, the company announced.

Godlasky took over from Roger Brooks at the end of 2005 as chairman and chief executive officer of AmerUs. Aviva acquired AmerUs in 2006 and appointed Godlasky as the president and chief executive officer of Aviva USA. In 2007, he was named chief executive, North America, leading Aviva’s American and Canadian operations.

Aviva has named Igal Mayer as CEO of its North America business, and Mark Hodges as CEO of its newly configured United Kingdom business, the company said today. The moves go into effect Jan. 1.

“Igal and Mark have done a great job in getting the best from our U.K. businesses and making them fit for the future,” said Andrew Moss, Aviva group chief executive. “The time is now right to bring them closer together to maximize their full potential in our home market.”

Mayer, who is currently CEO of Aviva’s U.K. general insurance business, will lead Aviva’s businesses in the United States and Canada, succeeding Godlasky. Prior to his current role, Mayer had been CEO of Aviva’s Canadian business.

Aviva tabbed Hodges to help lead the restructuring of its U.K. operations. Under the change, the company will bring its U.K. life and general insurance businesses under a single CEO and moniker in hopes of serving customers more effectively across the two businesses. Hodges is currently CEO of the U.K. life operations and a main board director of Aviva plc. Prior to his current position, Hodges was the managing director of Aviva’s U.K. general insurance business, and also spent seven years as its chief financial officer.

Robin Spencer will also take on a new role on Aviva’s executive committee as chief risk officer. Spencer is currently CEO of Aviva’s Canadian operations and was previously the chief financial officer in Canada.