"An unidentified assailant fatally stabbed [Vyacheslav Shirshov] in the stomach," a spokesman for the investigative committee said on Friday.
A criminal case has been opened into the murder. Investigations believe the attack may have been linked to Shirshov's professional activities. Shirshov, 36, was the director of the procurement department, which oversees contracts on raw materials for AvtoVAZ and selects suppliers.
Togliatti has a reputation for turf wars between criminal gangs seeking control over the lucrative auto industry.
French carmaker Renault, which already owns 25% in AvtoVAZ, announced plans in late December to buy 25% plus one share in the plant based in Togliatti, and could sign a final deal on February 25, when the French firm will buy a 12.8% stake in AvtoVAZ.