Marwood joined the company as retail director in 1996 and returned in 2002 following a three-year stint as MD of Newshops. He has been MD for nine years.
"Jerry's a real gent honest and with a lovely way of doing things," said one wholesaler. "He is held in high regard in the trade. It's not an easy job being MD of a decentralised organisation like Spar, but Jerry has made a good job of it."
Landmark Wholesale MD Martin Williams described Marwood as a "big asset to our sector".
Peter Blakemore, chairman of Spar Food Distributors and also MD of Spar wholesaler AF Blakemore & Son, added:
"Thanks to Jerry and his team, we have a strong business model and are trading successfully in a competitive market. At the moment the focus of the board is on ensuring we continue in this way."
The search has now started for a replacement. Spar has already recruited headhunters after informing the Spar team at its central office in Harrow, north west London, and its National Guild Board, of Marwood's decision this week. "As far as the search is concerned we are conducting the widest possible, and that includes internal," Marwood said. "We have some time so we want to get this right. We have a 'work to' target of mid-summer to have the new person in place but if it takes longer, then it takes longer. The emphasis is on a managed transition."
Until then, it was business as usual at Spar, Marwood added. "I still have a number of exciting business initiatives to implement," he said.
Marwood, who is ranked the third most powerful person in convenience on The Grocer's Power List, was also chairman of the Association of Convenience Stores in 2007. In the same year he was the first convenience figure to be presented with the The Grocer Cup for Outstanding Business Achievement.