The head of Telstra’s retail group, Karsten Wildberger (pictured), has resigned less than two months after replacing Gordon Ballantyne, who left in October.

The company said Wildberger was leaving for personal reasons and plans to return to Germany towards the middle of next year.

Wildberger joined Telstra in January 2013 as MD of the consumer group and was appointed MD of the products group in May. He was previously with Deutsche Telekom and Boston Consulting Group.

The Telstra retail business includes consumer and business divisions and product and digital business units and accounts for about 65 per cent of the company’s revenue and profit.

The operator has suffered a series of senior staffing losses this year after former CEO David Thodey resigned in February. Prior to the departure of Ballantyne, who was seen as a likely replacement for Thodey, international group MD Tim Chen quit in July and its head of cost-cutting Robert Nason left in April, the Sydney Morning Herald said.