The tie-up, the first time a third party has sold M&S products, also involves new subsidiary Amazon Services Europe hosting and providing the e-commerce technology behind M&S's website.
Elsewhere in the top five, bookmaker Stanley Leisure benefited from news that state-owned betting operator The Tote was considering a counter-bid for the chain's 600 betting shops.
Rival William Hill revealed its intention to buy the outlets for up to £700m last week. Stanley moved up ten places to third, while William Hill stayed second.
The US's biggest car makers, General Motors and Ford, joined MG Rover at the bottom of the table. Ford suffered after reporting a 38 per cent drop in first-quarter earnings, and a cut in production to reduce inventories.
General Motors fell 18 places on the back of a £580m first-quarter loss, blamed on a sharp drop in profits in Asia and a dispute over payments to Fiat.
The news that dealers may sue MG Rover directors kept the troubled UK car maker in the worst spot.
Reputation Monitor is compiled from Thomson Intermedia's National News Index, a measure of media sentiment that excludes stockmarket reports and passing mentions.