Jan. 29 (Bloomberg) -- Gruma SAB, Mexico’s largest maker of corn flour for tortillas, fell to a three-week low after Venezuelan President Hugo Chavez said last night his government will seize one of the company’s local units.

Chavez said his government will take control of Molinos Nacionales CA, the Venezuelan maker of Robin Hood flour known as Monaca, after authorities in November arrested a minority shareholder. Ricardo Fernandez Barrueco, a banker who owns a 24.14 percent stake in the unit, was arrested for allegedly diverting deposits from financial institutions that he owned and for failing to prove the origin of funds.

“What happened with Monaca? It’s being operated by us and needs to be passed into the government’s control,” Chavez said yesterday on state television. “He who slips, loses.”

Gruma sank 4.2 percent to 25.8 pesos in Mexico City trading, the lowest since Jan. 6. It earlier fell 10 percent, the most since March 5.

Gruma hasn’t received any official communication from the Venezuelan government, a spokesman who declined to be identified in accordance with company policy said today by telephone.

Venezuela may leave Gruma, which has a 72.86 percent stake in Monaca, with full operational control and only seize Fernandez’s stake in order to maintain stability in the food industry, HSBC Holdings Plc analyst Pedro Herrera said in a note to clients today.

“The government cannot afford major disruptions to food availability at this time,” Herrera wrote. “The food supply and distribution system of which Gruma is a part has been working well and it benefits the government to ensure that it continues to work.”

Gruma’s Venezuelan operations accounted for about 18 percent of total sales as of September 2009, according to the report. Gruma operates Monaca in Venezuela through a company called Valores Mundiales.

To contact the reporter on this story: Nathan Gill in New York at ngill4@bloomberg.net or Daniel Cancel in Caracas at dcancel@bloomberg.net.

Last Updated: January 29, 2010 16:51 EST