Peter Wallenberg, who was born in 1926, came from one of Sweden's most prominent families, with other relatives active in banking, politics, diplomacy and business.
His most famous relative was Raoul Wallenberg, a diplomat who saved tens of thousands of Jews from the Holocaust during World War Two and who went missing seventy years ago this weekend.
Peter Wallenberg had a long career in finance after graduating from law school. He worked in the UK, the US and Africa, before settling in Sweden and working on the board of several leading industrial companies including Electrolux and Ericsson. He also helped establish Anglo-Swedish drugmaker AstraZeneca in 1999.
Until earlier this month he had remained active in the Knut and Alice Wallenberg Foundation, a Sweden's largest private financial research organisation.
During the past five years, the foundation has granted a total of five billion kronor for various projects, mainly at Swedish universities.
"With deep regret, the Management Board of the Knut and Alice Wallenberg Foundation announce that its honorary president Peter Wallenberg died in his sleep at his home on Monday at the age of 88," said a statement from the foundation.
"Peter Wallenberg has been active on the board since 1971 and has held the presidency from 1982 until recently," it added.
Wallenberg became heavily involved in the foundation after his older brother Marc Wallenberg killed himself in 1971.
“Marc and I were very close,” he told Sweden's Sydsvenska Dagbladet newspaper back in 2006.
“I didn’t see what was coming, despite sitting talking to him two hours before he took his life. It was a big misfortune and I felt a terrible emptiness.”
Reacting to the news of Peter Wallenberg's death, Sweden's King Carl XVI Gustaf said in a written statement: "Peter Wallenberg has meant a lot to Swedish industry. He was also deeply involved in the Knut and Alice Wallenberg Foundation, which contributed to scientific development in Sweden. For the royal family, Peter was a close and loyal friend."
Sweden's Prime Minister Stefan Löfven said that he had "great respect" for the financier, who he said had played a "big role in Swedish business for decades."
Peter Wallenberg was married three times and leaves behind two sons.