Rafael Correa holds up a newspaper that reads 'The Cod Wins' at a news conference in Guayaquil

Partial results from Ecuador's presidential run-off show leftist economist Rafael Correa with a wide lead over billionaire conservative Alvaro Noboa.

With about half of the ballots from Sunday's vote counted, Correa has about 68 percent of the vote and Noboa around 32 percent. Final results could come Tuesday.

Correa claimed victory Sunday, and announced that under his leadership Ecuador would try to rejoin the Organization of Petroleum Exporting Countries, which it left in 1992.

In his campaign, he attacked U.S. policies, the World Bank and the International Monetary Fund, and has called for the constitution to be rewritten.

Noboa, a banana tycoon, has said he will wait for the final results. Both candidates ran on populist platforms with promises to improve the lives of Ecuador's poorest. The first round of voting was held last month.

If Correa wins the run-off, he would join a growing list of leftist presidents in South America, including those from Venezuela, Brazil, Argentina, Chile and Bolivia.

Some information for this report was provided by AFP, AP and Reuters.