He joined the supermarket giant from advertising agency Fallon and within months in his new role moved its £75m advertising account from Fallon to SFF stablemate Saatchi & Saatchi.
It is not known if the former chief strategy officer at Fallon has a job to go to. Asda is yet to find his replacement.
Sinnock’s appointment at Asda followed the appointment of former McCain Foods’ marketer Simon Eyles as head of Asda brand marketing. Sinnock and Eyles both reported to Asda chief marketing officer Rick Bendel. Bendel was promoted from marketing director to the position of CMO last year.
Sinnock was responsible for developing the marketing and customer strategy across the breadth of Asda’s marketing function, working alongside Katherine Paterson, Asda’s marketing director for communications.
His departure comes as the retailer continues to cede ground in the battle for Britain’s food.
In May, Wal-Mart owned Asda revealed a slump in like-for-like sales- down 0.3% in the first three months of the year – the first time that the supermarket’s sales declined since 2006. The setback came as Andy Clarke, the chief operating officer, took over from Andy Bond as chief executive.
This story first appeared on pitch