Swiss-based chocolate maker Lindt & Spruengli (LISP.S) is in advanced discussions to acquire family-owned U.S. candy business Russell Stover, and the two companies could announce an agreement as early as next week, the Financial Times reported on Saturday. Russell Stover, known for its boxed chocolates, is the third-largest U.S. candy company by sales. Lindt is the Swiss-based maker of Lindor chocolate balls and gold foil-wrapped chocolate bunnies.