* Maduro returning to Venezuela after visit with Chavez
* Socialist leader in Cuba, not heard from for three weeks
By Deisy Buitrago
CARACAS, Jan 1 (Reuters) - Venezuelan President Hugo Chavez is aware that his condition is complicated following a fourth cancer operation in Cuba, Vice President Nicolas Maduro said on Tuesday, as the OPEC nation watches for clues to the socialist leader's health.
Maduro said he was returning to Venezuela after spending several days alongside Chavez and members of the president's family. That may help squelch rumors his visit was a sign that the former soldier was near death.
"During these days I was able to see him twice and speak with him," Maduro said during an interview from Havana with regional television network Telesur. "He is completely conscious of the complexity of his post-operative state and he expressly asked us keep the people informed."
Maduro, who Chavez last month designated as his successor, said the president had grasped his hand "with immense strength" as they spoke, and asked him about the state of the economy and the swearing-in of newly elected governors.
"After staying in Havana to accompany the family members, we are returning to Caracas tomorrow (Jan. 2) to continue our work," said Maduro, who visited Chavez with his wife, Attorney General Cilia Flores.
The president suffered unexpected bleeding as result of the complex, six-hour operation on his pelvic region Dec. 11, and later had to fight off a respiratory infection.
On Sunday, Maduro had said the 58-year-old Chavez was suffering a third set of complications as a result of the respiratory problem.
Chavez's son-in-law, who also serves as science minister, on Monday said the president was in stable condition and urged Venezuelans to ignore rumors of his impending death.
Chavez has never said what type of cancer he has.
His death or resignation due to illness would roil politics in Venezuela, where his personalized brand of oil-financed socialism has made him a hero to the poor majority but a nemesis to critics who call him a dictator.
If Chavez stepped down, new elections would be called within 30 days. Maduro would be the ruling Socialist Party candidate.
Chavez's condition is also being watched closely by Latin American countries that have benefited from his generous assistance, as well as Wall Street investors who are drawn to Venezuela's lucrative and heavily traded bonds.
He is due to be sworn in again in Venezuela on Jan. 10 after winning re-election in October. But Socialist Party officials have suggested the ceremony could be delayed if he were unable to return in time.
Opposition leaders say postponing it would show Chavez is not fit to govern and that new elections should be held to choose his replacement.