President Vladimir Putin, the first Russian leader to make an official visit to Mexico, and his Mexican counterpart discussed proposals to build a Russian helicopter factory and a heavy machinery assembly plant. Putin said Russia was also eager to invest in Mexico's cash-hungry but largely closed energy sector.

"These are concrete, interesting projects, though small ones, and we are going to support them," Putin said after meeting with President Vicente Fox. "But I think that other projects could be of wider scope because some Russian companies already operate in the energy market."

Although Mexico's energy sector is largely closed to foreign investment, Russia is already a supplier of natural gas to Mexican power plants.

Putin said Russia hoped to supply liquefied natural gas to gas vaporization terminals that major oil companies are vying to build along Mexico's Pacific coast, to provide an alternative to costly U.S. gas imports.

Putin also said Russia wanted to become involved in oil exploration in Mexico, which now is limited to the state oil monopoly, Pemex.

The two leaders signed several bilateral trade agreements and agreed to study the building of a helicopter maintenance center as a first step toward the construction of a helicopter assembly plant in Veracruz state.

On Tuesday, Putin will attend an economic summit for leaders of the Group of Eight industrialized powers in Sea Island, Ga.