Canadian billionaire and renowned art collector Kenneth Thomson, who led his inherited empire to become one of the world's leading electronic publishers, has died. He was 82.

The former Thomson Corp. chairman and the company's controlling shareholder, collapsed in his Toronto office Monday morning.

A spokesman said he died of an apparent heart attack at about 8 a.m.

"This is a very sad day for all of us at The Thomson Corp.," President and CEO Richard J. Harrington said in a written statement.

"I had the special privilege of knowing Ken Thomson for 20 years. He was a remarkable man who did so much to build this business by constantly investing in the future. He was a strong leader whose energy and enthusiasm for Thomson was contagious. Anyone who met Ken was touched by his grace, charm and humility. He will be missed."

Thomson was born on Sept. 1, 1923 in Toronto, Ont. as the third child and only son of Roy and Edna Thomson.

He spent his formative years in North Bay and Toronto, where he attended Upper Canada College as a young man.

After serving with the Royal Canadian Air Force during the Second World War, Thomson attended Cambridge University.

The Thomson empire is a rags-to-riches story that began in 1930 when Ken Thomson was a young boy.

His father Roy Thomson, the son of a barber, obtained a franchise to sell radios in Northern Ontario in 1930.

Nearly three decades years later he had acquired 15 British newspapers, including the Sunday Times.

Roy Thomson took the company public in 1965 and continued his acquisitions spree in Britain with the purchase of the Times of London in 1967.

Following his father's death in 1976, Ken Thomson took over the family business.

"He was a business man who was brought into the company by his father and expected to run this very large and growing business," Thomson biographer Vic Parsons said.

"But on the other hand he had another side -- he was a sports fan, an art collector and he was very, very shy."

Under his leadership, the media empire evolved to become one of the world's most powerful information services and academic publishing companies with 2005 revenues of $9.6 billion.

The corporation, with 40,500 employees and 2005 revenue of $8.5 billion US, now has its operational headquarters in Stamford, Conn., although its formal head office remains in Toronto.

He had been chairman of the electronic-publishing giant from 1978 until his retirement in 2002, when he was succeeded by his eldest son David.

"We will miss his support and companionship terribly," David Thomson said Monday.

"All of my grandfather's family are deeply grateful to my father for his wise stewardship of our family interests for more than 30 years. More importantly, he was a gentle and kind man who impressed everyone with whom he came in contact. He was much loved."

Public condolences

Thomson was also remembered by Prime Minister Stephen Harper as one of Canada's most successful businessmen.

"He was a great Canadian," Harper told reporters Monday. "We want to pass on our condolences to his family."

In a written statement, Harper said Thomson "combined his financial acumen with his commitment to serve both his country and his community."

Ken Thomson often said he wanted to be remembered as the head of an organization his father would have been proud of.

Unlike his father though, who relished his peerage and gave up his Canadian citizenship to be appointed to Britain's House of Lords, Ken Thomson did not use his hereditary title in Canada.

At the time of his death, Thomson served as chairman of The Woodbridge Co. Ltd, the family's private investment company, and controlled about 70 per cent of Thomson's outstanding common shares. That control remains with the Thomson family.

In addition to the Thomson Corp. interest, Woodbridge's holdings include 40 per cent of telecommunications giant Bell Globemedia, owner of the CTV network and the Globe and Mail.

Bell Globemedia President and CEO Ivan Fecan expressed his condolences to the Thomson family in a statement sent to CTV staff.

"Under Ken's leadership, the Thomsons have been part of this company and its success since its inception in 2001," Fecan wrote.

"Please join with me in sending our sincerest condolences to Ken's wife Marilyn, their children David, Taylor and Peter and the entire Thomson family."

Woodbridge President W. Geoffrey Beattie said the Thomson family had no intention of shifting its support for the Thomson Corp.

"Ken Thomson put the utmost importance on being a supportive shareholder of The Thomson Corp.," Beattie said.

"The plans which now come into effect will ensure that the Thomson family's ownership position will be as solid, supportive and unified as ever before."

Private interests

Though Thomson kept a relatively low profile, he distinguished himself as one of North America's leading art collectors and a major benefactor to Toronto's Art Gallery of Ontario.

"Ken's life as a collector was about how people and art interact," Art Gallery of Ontario CEO and Director Matthew Teitelbaum told CTV Newsnet. "It was an empathetic process because Ken himself felt deeply about the role that art played in his life."

"He did a great job in putting together collections of great importance."

Thomson was also an avid dog lover and walker.

"He used to walk dogs for the Toronto Humane Society as a volunteer," Parsons said.

In 2005, Forbes Magazine ranked Thomson as the ninth richest person in the world and Canadian Business magazine named Thomson and his family as the wealthiest in Canada with personal assets estimated around $22.6 billion.

Thomson is survived by his wife Marilyn, his three children David, Taylor, and Peter and their families; and his sister Audrey Campbell. Thomson was predeceased by another sister, Irma Brydson.

A memorial service will be held on a date which has yet to be announced.