* German businessman survived by wife and five children
* Funeral took place in November, family says
* Berthold Albrecht was one of richest men in Europe
FRANKFURT, Dec 7 (Reuters) - German billionaire Berthold Albrecht, who became one of Europe's richest men after he and his brother Theo Jr inherited the Aldi discount supermarket chain, has died aged 58, his family announced on Friday.
The brothers' fortune, held by a family foundation, was estimated at $17.8 billion by Forbes, placing them 32nd in its list of billionaires.
Their wealth came courtesy of their father, Aldi co-founder Theo Albrecht, who died aged 88 in July 2010.
After the Second World War, Theo and his brother Karl turned the small grocery store their mother operated in Essen into one of the nation's largest food retail chains with their focus on a limited selection of bargain goods in sparse stores.
"Berthold was a fighter, and full of hope to the end," his wife, Babette, wrote in a full-page notice published in several German newspapers, indicating that he had been ill for some time.
The family has taken a back seat from day-to-day operations at Aldi since 1993, when Theo Snr appointed managers from outside the family, and Berthold's death is unlikely to have any significant impact on the company
"There will be no change to the operational business," Westend Brokers analyst Klaus Kraenzle said, highlighting how the reins to external managers had been handed over already. "Management is aware of the challenges they are facing from Lidl, which is acting very agressively."
The dominance of the German food retail market by discounters Aldi and Lidl has made it difficult for outside players to make money from supermarkets in Europe's largest economy, with even the mighty Wal-Mart having to concede defeat.
Aldi was split into two divisions covering north and south Germany in 1960. Theo took the north and Karl the south. Karl, aged 92, is classified by Forbes as the richest man in Germany, with a fortune of $25.4 billion.
Friday's notice from the notoriously reclusive family said that Berthold's funeral had taken place in November, but it did not give further details of the circumstances of his death.
The family has fiercely guarded its privacy since the kidnapping of Theo for 17 days in 1971. He was eventually released after a ransom of about $3 million was paid.
True to his thrifty principles, Theo then went to court to have the ransom classified as a tax-deductible business expense.
The Aldi empire, which has estimated worldwide annual turnover of about 50 billion euros ($65 billion), also owns the Trader Joe's grocery chain in the United States. In Europe, it competes with the likes of Tesco, Carrefour and Metro.
Berthold worked on the supervisory board of directors at Aldi North, where he had a particular interest in Trader Joe's.
"He knew how to give the group the means to push forward into the future," Aldi Nord said in a announcement. "He was liked by everyone."
Berthold is survived by his wife, five children and the family dog, who was also mentioned in Friday's announcement.