Chavez said the move was to tackle a housing shortage
President Hugo Chavez has announced the immediate nationalisation of Venezuela's entire cement industry.
In a TV address, he said his government could not allow private companies to export cement that was needed to tackle a severe housing shortage.
Mr Chavez promised they would be paid fair compensation for the forthcoming state takeover of what he described as a strategic industry.
Three of Venezuela's largest cement companies are foreign-owned.
Mexico's Cemex has almost half the market, with most of the remainder controlled by Lafarge of France and Switzerland's Holcim.
Mexico said it would do everything possible to protect the interests of companies operating abroad.
The Mexican Finance Minister, Agustin Carstens, condemned the Venezuelan measure, saying it showed a lack of respect for property rights.
Holcim said it took Mr Chavez's announcement very seriously.
"But we stay calm because this is not the first time that (the Venezuelan president) announces that the sector is going to be nationalised. We have to wait and see what happens," a Holcim spokesman said.
Holcim has two plants in Venezuela with annual capacity of three million tonnes - 1.5% of the group's total capacity and 1% of its global revenues.
In 2006, Venezuela enacted a law forcing foreign oil companies to give the state energy group, PDVSA, at least a 60% share in their Venezuelan operations.
The country has also begun nationalising its electricity, telecommunications and natural gas industries as part of Mr Chavez's drive toward "21st century socialism".