The factory has 170 employees, and an additional 250 people are expected to be hired by the end of this year.
This is the company's second chocolate factory in the Ulyanovsk region - the company opened a pet food factory in the area in 2009.
Mars, based in McLean, Virginia, has net sales of more than $30bn and it has six business segments including pet care, chocolate, Wrigley, food, drinks and Symbioscience.
