UPDATE 7-Ecuador's Correa claims re-election victory

(For full coverage of the election, click on [ID:nN26486483])

* Incumbent Correa claims victory

* Exit polls show he took more than 50 percent of vote

* Slowing economy threatens spending, leader's popularity

* Correa vows to stand up to foreign investors, companies (Changes dateline, adds details, new quotes)

By Alexandra Valencia

GUAYAQUIL, Ecuador, April 26 (Reuters) - Ecuador's President Rafael Correa claimed an easy re-election victory on Sunday as voters ignored a sputtering economy to give the charismatic socialist four more years in power.

Correa, a popular former economy minister, won more than 50 percent of the vote, two leading pollsters said. The result put him way ahead of his nearest rival and means he comfortably avoided a run-off election.

"This revolution is on the march, and nobody and nothing can stop us," the 46-year-old president said minutes after exit polls showed he won easily.

"The people ... have given us the most splendorous victory of probably the last 50 years," Correa said at a news conference in his home town of Guayaquil.

A Correa victory in line with the polls would be the first time a president has won an election without a run-off vote since Ecuador's democracy began in 1979. Flag-waving supporters packed Correa's party headquarters shouting "Just one round, Ecuador."

Correa has vowed to keep standing up to foreign investors and big oil companies in a second, four-year term after bringing relative stability to a country where street protests toppled three presidents in the decade before he took office in 2007.

But the fierce nationalist must now tackle a weakening economy and sliding oil revenues to deliver on his promises of more housing, roads and jobs or he risks eroding his popularity in the world's top banana exporter.

A new constitution passed in September gave Correa broader powers, allowed him to stand for re-election and also lets him run for another four-year term in 2013.

"Correa is being watched by all Ecuadoreans and should continue with adequate social spending. If not, his administration will not last long," said veterinarian Karen Cabrera, 32.

FORMIDABLE TASK

A close ally of Venezuela's socialist President Hugo Chavez, Correa was also hoping to win a majority in the newly formed National Assembly after a lively campaign in which the boisterous incumbent frequently burst into song.

He is trusted by Ecuador's poor for squeezing hundreds of millions of dollars from foreign companies and spending it on pensions, schools and health programs in the country of 14 million people known for its Galapagos Islands, Andean mountains and remote Amazon tribes.

Correa is a bold leader who has made risky moves such as defaulting on billions of dollars of debt and also reining in his own left-wing party's radicals, who oppose his plans to develop gold mines in partnership with the private sector.

He is closing down a U.S. airbase used for anti-drug flights and in February expelled two American diplomats, but he says he respects "sincere" U.S. President Barack Obama.

A former missionary inspired by a left-wing strand of Roman Catholic teaching known as Liberation Theology, Correa has followed the lead of other Andean leaders such as Chavez and Colombia's conservative President Alvaro Uribe, who also changed their nations' constitutions to stay in office longer.

Opponents accuse the sometimes hot-headed leader of autocratic tendencies and say he is damaging the country with the debt default and heavy spending.

Critics say planned changes to Ecuador's highest court will give too much power to the president, and criticize a new law due to be passed this year that will force banks to reduce holdings in the country's main media groups.

Correa says it will take 80 years for his "citizens' revolution" to truly change Ecuador.

But the Belgian and U.S.-educated economist faces a formidable task keeping supporters happy as lower oil revenues bite into government finances. Foreign reserves have halved in the last six months, unemployment is up and growth has slowed.

If the economy fails to improve he may have to make tricky decisions about spending cuts. The government last week asked holders of Ecuador's $3.2 billion in defaulted bonds to accept a proposal to buy back the debt at a heavy discount.

"The republic may need to balance its social and employment goals with budgetary constraints," the government said, citing risks of lower oil income and limited access to debt markets.

Ecuador uses the dollar as its currency and can not print money to cover economic problems.

(Additional reporting by Maria Eugenia Tello, Writing by Fank Jack Daniel; Editing by Kieran Murray and Philip Barbara)