Johanna Quandt: Businesswoman who carried on the work of her husband Herbert, the head of BMW, following his death in 1982

Quandt inherited a 16.7 per cent stake in the Munich-based firm

Quandt: she set up a foundation to help young people become business journalists (Getty Images)

Johanna Quandt was a billionairess whose husband turned BMW into one of the world's biggest makers of luxury cars. She was the third wife and former secretary of Herbert Quandt, inheriting a 16.7 per cent stake in the Munich-based firm when her husband died in 1982. She also owned a stake in Datacard Group, a Minnesota-based credit-card and passport maker, and held shares in Gemalto, a security-software design firm based in Amsterdam.

Her net worth of around £7.3bn made her Germany's eighth richest person. BMW has a market value of about $43bn (£27.5bn), and manufactures, among other makes, BMW, Mini and Rolls-Royce. With her two children, Quandt held a joint 46.8 per cent stake.

"As an entrepreneur, you fulfilled the tasks that fell to you after the death of Herbert Quandt, in an unspectacular and even Prussian-like conscientious way," her son Stefan said in a speech for her 80th birthday. Quandt, who rarely spoke to the media, stayed on BMW's supervisory board until 1997.

In 2007, a documentary explored the family's ties to the Nazis. Quandt's father-in-law, Günther, made Mauser firearms and anti-aircraft missiles. The family commissioned a history professor to examine their involvement; he found that forced labour had been used.

She was born in 1926 in Berlin; her parents were art historians. After leaving school she began an apprenticeship in medical technology then worked as a banker's secretary before joining Herbert Quandt's office in Bad Homburg, near Frankfurt, in the mid-1950s.

Herbert and his half-brother Harald had inherited a portfolio of about 200 companies, including stakes in Daimler and BMW, after Günther's death in 1954. Within a few years Johanna was Herbert's personal assistant, with increasing influence over his business decisions. In 1959, against the advice of his bankers, Herbert was persuaded by employees and some smaller shareholders to boost his stake in the almost-bankrupt BMW to 50 per cent in order to fend off a takeover attempt by Daimler. The plan saved the car-maker from collapse.

In 1995 Quandt set up a foundation which supports young people training to become business journalists. She provided funding to help children with cancer and financed cultural groups staging art exhibitions. In 2012 she committed around €40m (£28m) over a 10-year period to a Berlin institute for health-care research.

DAVID DE JONG

Johanna Maria Bruhn, businesswoman: born Berlin 21 June 1926; married 1960 Herbert Quandt (died 1982: two children); died Bad Homburg, Germany 3 August 2015.

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