US-based cereal maker Kellogg says it is pulling out of Venezuela because of the economic deterioration in the country.
Workers said they were prevented from entering the plant in the central city of Maracay on Tuesday.
The announcement comes ahead of Sunday's presidential elections.
President Nicolas Maduro, who is standing for re-election, told a rally that he would hand control of the factory over to the workers.
"We've begun judicial proceedings against the business leaders of Kellogg's because their exit is unconstitutional," Mr Maduro told cheering supporters in the central state of Carabobo.
"I've taken the decision to deliver the company to the workers in order that they can continue producing for the people."
Venezuela's battered economy has been hit by falling oil revenue and the plummeting value of its currency, the bolivar.
It has one of the highest rates of inflation in the world. In the year to the end of February 2018, prices rose by more than 6,000%, according to the opposition-dominated National Assembly.
Kellogg is the latest multinational to close or scale back operations in Venezuela, citing strict currency controls, a lack of raw materials and soaring inflation.
It said it hoped to return to Venezuela in the future and warned against sales of its brands "without the expressed authorisation of the Kellogg Company".
In 2016, Venezuela's government took over a plant belonging to US-based hygiene products manufacturer Kimberly-Clark after it announced it was stopping operations because it could not obtain raw materials.
The Texas-based firm recently requested the start of arbitration proceedings against Venezuela at the World Bank.
President Maduro, who has been in office since 2013, blames Venezuela's problems on an "economic war" being waged by foreign governments and businesses. His critics say government mismanagement is the chief cause.