Ecuador's president, Rafael Correa, has won a referendum on a new constitution that will implement leftist reforms, including increased state control over monetary and oil policy.

Preliminary results showed 65% approval, with almost half of the votes counted. An opposition leader told Reuters than Correa had won.

Correa is an ally of the socialist regimes in Venezuela and Bolivia, although his reforms are less radical than those of Hugo Chávez or Evo Morales.

The new constitution contains a number of provisions aimed at the 38% of Ecuadorians who live below the poverty line. It guarantees free education up to and including university, increased spending on health, low-interest micro-loans, building materials for first-time homeowners and free seeds for growing crops.

Correa is also granted greater control over the central bank and army, and the right to stand for two more consecutive terms.

"We're making history! Onward!" a jubilant Correa proclaimed in his coastal hometown of Guayaquil as the scale of his victory became clear. "This is confirmation of the citizens' revolution we're offering."

Correa, 45, called it a "clear, historic victory" and urged Ecuadoreans to help him "achieve a brave, sovereign and dignified homeland equitable, just and without misery".

The former finance minister has said the document will help to eradicate a political class that has made Ecuador one of Latin America's most corrupt countries.

Correa has already taken a tough stance with oil companies, which he wants to accept a flat fee for extraction with no share of profits. Before a likely general election early next year, he hopes to pass a new law that will regulate mining, which he says will attract investment.

The US-trained economist once described George Bush as "dimwitted" and, in reference to Chávez calling the US president the devil, Correa said: "Calling Bush the devil offends the devil." Those comments, his policies while in office and the use of a referendum to boost his powers, including his potential time in office, have prompted unflattering comparisons with Chávez.

But, while he counts Chávez as a friend, he has said Ecuador is not part of the same political movement and, unlike the Venezuelan leader, he has not moved to nationalise utilities such as telecommunications and electricity.

And while Correa has opted not to renew a lease that allows US anti-drugs missions to fly out of a coastal airport in Manta, US diplomats have praised Ecuador's drug-fighting co-operation.