Derwent Group Holdings, the property development firm he owned released a statement to confirm his death. It said: "It is with the greatest sadness that we have to announce the death of our founder Albert Gubay.
"He had been ill for some time, but happily his close family were with him at the end.
"In due course more information will be supplied regarding his life, his legacy and the future of The Derwent Group, but for now all our thoughts are with his wife Carmel, his children and grandchildren."
Before earning his millions, Mr Gubay made a 'pact with God' in which he said he would give half his money to the Catholic Church if he became rich.
He gave an interview to the BBC in which he said: "One Saturday, I didn't know where the next penny was coming from and I lay on my bed and I had this conversation with God."
"I said 'God, help me and whatever I make over the years of my life, when I die, half will go to the Church.'"
Some 40 years later at the age of 82 he fulfilled the promise giving almost his entire £480 million estate to a new charitable foundation, keeping under £10 million to see out his old age.
The foundation will give half to Catholic causes and half to charitable projects at the trustees discretion.
In 2011 he was given a papal knighthood for his charitable work.