Back will move up on September 1, succeeding to a role which von Spreckelsen took on after Alan Smith relinquished it in October 2002.
At the time, the company said it had decided to focus control with von Spreckelsen because having two hands-on bosses was creating confusion.
But von Spreckelsen said this week: “When I combined the role it was always a temporary arrangement. My commitment will fall to three days a week.”
Back joined Somerfield in November 2002 from Budgens where he had worked for nine years, rising to become group finance and logistics director. He worked under von Spreckelsen at Budgens while he was chief executive there.
Back will be replaced by David Cheyne, currently head of the convenience business and MD of Aberness, acquired by Somerfield in March. He retains his current responsibilities.
Cheyne joined the multiple in November from Alldays, where he was commercial director.
Katie Bickerstaffe, head of Somerfield Business, has joined the board as director of Somerfield stores and retail services.