King, who had responsibility for all Asda’s retail and supply chain operations including distribution, customer service and internal communications, joined Asda in November last year to replace Andy Clarke after he was promoted to CEO.
An Asda spokeswoman confirmed that Clarke had said the appointment “wasn’t working out”.
In a statement, Asda says: “Sometimes, it just doesn’t work out. Clearly whilst Simon has considerable talents and retail experience, we felt his impact wasn’t being realised as quickly as we hoped. We wish him well for the future and appreciate all his hard work over the past five months.”
Asda expects to name his replacement by the end of the month, but could not say whether the appointment would be made internally or not.
At the time, King was seen as the final appointment of Asda’s new executive committee following the departure of former CEO Andy Bond.
He joined from Saudi Arabian supermarket and hypermarket operator Panda Retail, a part of The Savola Group.
Previously he was CEO of Tesco Kipa in Turkey and has worked in Tesco’s international operations in South Korea, the Czech Republic, Slovakia, Poland and Hungary.