In reading Vassal State (mentioned in the books posting) I was surprised to see this. I probably should have kept up on this but was just thinking Hersheys in terms of American chocolate, so:
In the confectionery aisle there are chocolates and sweets from Cadbury of Bournville, the UK’s market leader. An online search confirms it is fully owned by Mondelez of Chicago. That Illinois company also owns best-selling brands Milka, Oreo and Toblerone. Dozens more sweets come from Mars, Incorporated of Virginia, which owns Wrigley, Galaxy and Maltesers.
(Hanton, Angus. Vassal State: How America Runs Britain (pp. 12-13). Swift Press.)
Incidentally the first few chapters cover just about everything in the supermarket in terms of American ultimate ownership. It makes for breathtaking reading.