* Di Stefano dies two days after suffering heart attack
* Considered one of the greatest footballers of all time
* Tributes pour in from soccer world and beyond (Adds reaction, background)
By Sarah White
MADRID, July 7 (Reuters) - Former Real Madrid forward Alfredo Di Stefano, 88, one of the greatest footballers of all time, has died in the Spanish capital two days after suffering a heart attack.
Real's honorary president passed away at the Gregorio Maranon hospital at 1515 GMT on Monday, the club said in a statement.
"It's a very sad day," Real forward and World Player of the Year Cristiano Ronaldo said on his Twitter feed in one of an avalanche of tributes that poured in after the news broke. "For me, for all the Madridistas, for the world of football."
Ronaldo's predecessor as World Player, Lionel Messi, said on Facebook: "The world lost a legend today, Don Alfredo Di Stefano. An amazing man on and off the field."
Argentina-born Di Stefano, who helped transform Real into one of the world's leading teams in the 1950s and 60s, was admitted to intensive care on Saturday.
He had suffered an 18-minute respiratory arrest, the emergency services said.
"He was the most complete player I've ever seen," FIFA president Sepp Blatter said on the website of soccer's world governing body (www.fifa.com). "He was also my favourite player.
"I was following him very closely when he was playing for the great Real Madrid team and I was a young sports reporter. Later I had the privilege to meet him ... and we became good friends in football. I will always remember him."
Known as 'La Saeta Rubia' (blond arrow), Di Stefano joined Real in 1953 and became a naturalised Spaniard three years later.
He helped the club win five successive European Cups between 1956-60 and scored in each of the finals. His death comes just weeks after Real won their 10th European crown.
Di Stefano's international career was less spectacular and he made a handful of appearances for Argentina and later Colombia, while he was playing club football there, before netting 23 goals in 31 games for Spain.
He had a number of health problems in recent years and was fitted with a pacemaker in 2005 after heart surgery.
"A legendary player, a myth," Spanish state secretary for sport Miguel Cardenal said in a statement.
"There was nobody who stood comparison. He laid the foundations of a team that was named the best of the 20th century and that this year won the European Champions League.
"The legacy he left in Real Madrid's DNA was of fighting to the end and never giving up. Don Alfredo was the greatest."
Real president Florentino Perez announced that, according to the wishes of Di Stefano's family, the body would lie in repose at the club's Bernabeu stadium on Tuesday.
"Today is a day that we never thought could come, a day of absolute sadness for the Madrid family and the world of football," Perez told a news conference.
"The greatest Real Madrid player and the best of all time has left us," added the construction magnate.
"His legend will last forever. Alfredo Di Stefano changed the history of this club. He is a myth and he is Real Madrid." (Additional reporting by Iain Rogers, editing by Sarah Morris and Tony Jimenez)