Empain, who headed the Empain-Schneider group in the 1970s, died Wednesday in hospital in Pontoise, northwest of Paris, Diane Empain said on Facebook, confirming Belgian media reports.
“I would like to thank the intensive care unit and all the hospital staff of this unit,” she said on her Facebook page.
An Empain-Schneider CEO from 1971-81, Empain was the grandson of Edouard Empain, ennobled by Belgium's King Leopold II, who built an industrial empire in the late 19th century. The company constructed the Congolese rail network and the Paris Metro.
The group was worth billions by the late 1970s, employing 150,000 people and comprising 300 firms.
Empain became famous after his abduction in broad daylight in front of his Paris apartment on January 23, 1978. He was held hostage for 63 days, during
which time he chained up in a hideaway in a Paris suburb and starved, beaten and tortured.
The case grabbed public attention particularly after the kidnappers sent one of his fingers along with a ransom demand for a colossal 80 million francs.
A botched rendezvous to hand over the money turned into a two-day chase, with one of the kidnappers shot dead while another and two police officers were wounded.
The arrested kidnapper, Alain Caillol (see below), then asked his accomplices to release Empain, who was later found wandering around Paris. He had lost 20 kilogrammes (44 pounds) in weight.
Alain Caillol, Empain's kidnapper. Photo: AFP
'Man of exceptional courage'
Following his ordeal, Empain quickly withdrew from business, bitter that his kidnapping had not evoked sympathy on grounds that he had “disturbed” the establishment in France.
“I had plenty of friends who were willing to pay (the ransom), but since I did not have to come back, I did not have to pay,” he said in 2014 in an interview with Belgian newspaper L'Echo.
He told the paper that at the time Belgium's King Baudouin was ready to pay for his release because of “what the Belgian crown owed the Empain family”.
The king informed his company but it did not respond, according to Empain.
In 2012, Caillol told of the kidnapping in the book “Lumiere” and said the abductors had “reverse Stockholm syndrome” towards their victim.
“I wanted to tell Mr Empain of the respect we had for him,” Caillol told AFP.
Baron Empain in 2003. Photo: AFP
“It's been bothering me for a long time, I did not want to die or him to die without telling him the truth,” he said.
“I recently saw Mr Empain, it went well. He addressed me first, I couldn't do it.
“We talked about things .. we shook hands,” Caillol said.
During the kidnapping, the abductors discovered he was “a man of exceptional courage”, according to Caillol.
“There was an inverted Stockholm syndrome, he dominated us morally, everyone saw in him the dream of what he wanted to be: handsome, rich, powerful, intelligent …”
Empain's funeral will be held on June 29 at the church of Saint Georges de Bouffemont, just north of Paris, and he will be buried in the local cemetery, Diane Empain said.