* Chavez has been fighting cancer since 2011
* Has not been seen in public since December
* Chose Maduro as his preferred successor (Adds background, details, byline)
By Eduardo Garcia and Alexandra Valencia
QUITO, Feb 21 (Reuters) - Ecuador's President Rafael Correa said on Thursday that Venezuela's Hugo Chavez is recovering from cancer surgery, but if he had to step down Vice President Nicolas Maduro would be "extremely capable" of running the OPEC nation.
Correa, who won a sweeping re-election victory on Sunday, told Reuters he thinks Maduro is the right person to take over in Venezuela if the socialist leader needs to step down.
"Regardless of who may take charge, my main concern is that Chavez recovers ... but in case he cannot be in charge, Vice President Maduro is extremely capable," Correa told Reuters in an interview.
Chavez made a surprise return home from Cuba on Monday after undergoing his fourth cancer operation in 18 months on Dec. 11. He has never said exactly what type of cancer he has, only that it was diagnosed in his pelvic area in mid-2011.
The 58-year-old leader has named Maduro, a former bus driver and union activist, as his preferred successor if he had to step down and a new presidential election were held.
Correa said he believed any future transition of power in Caracas would be democratic if Chavez had to step down.
"All the processes since Chavez has been in power, as far as I know, have been extremely democratic. Those who lose might not like it, that's another issue ... But Venezuela has a vibrant democracy," he said.
Correa, a close friend and ally of Chavez, said he spoke with Maduro on Wednesday and plans to visit Venezuela soon.
Bolivian President Evo Morales said on Wednesday he had been unable to see Chavez when he visited Caracas this week because the Venezuelan leader was receiving treatment. (Editing by Daniel Wallis and Eric Walsh)