Hugo Chávez, Venezuela’s combative leftist president, announced a “very large” offshore natural gas find on Friday, which he said would propel the country into the ranks of the world’s biggest gas producers.

Mr Chávez, who met the Spanish king and prime minister at the end of a controversial international tour in which he was offered tanks and other weapons by Russia, said an area in the Gulf of Venezuela being explored by Repsol of Spain and Eni of Italy could yield seven to eight trillion cubic feet (tcf) of gas – four times previous estimates.

“It’s a very large quantity,” he said in an interview with El País published online. Repsol confirmed that everything pointed to Mr Chávez’s figure being correct, although further tests were needed, and that the find was equivalent to more than five years of Spanish gas consumption.

Venezuela’s announcement was the second major Latin America find unveiled this week. Brazil’s Petrobras said on Wednesday that its Guará field contained oil and gas equivalent to 1.1-2bn barrels of oil. At 8 tcf, Venezuela’s would equate to 1.44bn barrels of oil. “A discovery of this magnitude is a massive boost for Venezuela,” said Scott Pearson, Latin America upstream analyst at Wood Mackenzie.

International oil companies and other investors are simultaneously awed and anxious about Venezuela’s energy wealth. Mr Chávez sees himself as a revolutionary, has steadily become more authoritarian during his decade in power, and has nationalised various foreign assets, including the local operation of Spain’s Banco Santander.

Mr Chávez’s announcement, made in the presence of Antonio Brufau, Repsol chairman, was the dramatic finale to a self-invited visit that had Spanish leaders wincing with embarrassment.

“You’ve grown a beard, like Fidel [Castro],” an ebullient Mr Chávez told King Juan Carlos, the monarch who famously told him in public to “shut up” after he described a former Spanish prime minister as a fascist at a summit meeting two years ago.