The Wards, the family that bought Russell Stover from its founders in 1960, put it up for sale earlier this year and hired Goldman Sachs Group to execute the deal.
Zurich-based Lindt & Sprüngli said it was buying the Kansas-based company but did not disclose the price of the acquisition.
The Wall Street Journal reported on Sunday that the price would be around $1.5 billion.
Russell Stover became famous internationally when its chocolates were featured in the 1994 feature film "Forrest Gump" with Tom Hanks in the title role.
Gump sits on a park bench and exclaims, "My momma always said, life was like a box of chocolates — you never know what you're gonna get."
In the scene Hanks' character has a box of Russell Stover chocolates in his lap.
The takeover will make the Swiss company, which reported record profits in 2013, the number three chocolate maker in North America.
The company earlier signalled international ambitions to expand its presence in markets including North and South America.