Even for a company that once had the global monopoly on diamond production during almost a century of all but constant expansion, the collapse in commodities prices is proving too much.

Anglo American Plc, a conglomerate spanning everything from brewing, publishing and gold mining during its peak in the early 1990s, will shrink beyond recognition after Chief Executive Officer Mark Cutifani on Tuesday announced a package of asset sales, mine closures and job cuts. Among the potential casualties is Minas Rio, a Brazilian iron-ore mine where spiraling costs and collapsing prices turned a $14 billion project into the epitome of the company’s predicament.

“Minas Rio is the high water mark of their mistakes,” said Jeremy Wrathall, head of global natural resources at Investec Plc. “It was a series of strategic errors, the collective madness of the super cycle where everyone got it wrong.”

Like banks before the financial crisis or energy companies before the collapse of oil prices, Anglo American is the classic tale of over-extending during the good times only to be left with too much debt and too little money when markets take a dive.

85,000 Jobs

Anglo American will eventually employ 50,000 people, 85,000 fewer than now, Cutifani said. It will control a maximum of 25 assets, down from 55 today. Any mines that don’t make money will be put up for sale or simply shut.

Still, banks including HSBC Holdings Plc, said even these drastic cuts might not be enough should weak commodity prices prevail. Anglo fell as much as 14 percent on Wednesday to a record low in London, before paring losses to 2 percent. The stock slumped 73 percent in London this year, overtaking Glencore Plc as the worst performer in the benchmark FTSE 100 Index.

The announcement comes after Lonmin Plc, another U.K.-based mining company focused on Africa, last month was forced to tap shareholders to stave off collapse. Its businesses spanned gold mining, hotels, textiles and newspapers in the 1980s.

Anglo American’s assets “must deliver cash through the cycle,” Cutifani, 57, an Australian who has been in the top job at the company since 2013, told investors on Tuesday. “If not, they will not be in the portfolio. It’s as simple as that.”

At the company’s financial peak in 2007, when the price of platinum and nickel were near records, annual profit was $7.3 billion and its stock market value exceeded more than $80 billion. Analysts forecast Anglo American will lose $2.8 billion for this year; Cutifani told shareholders there won’t be a dividend until at least 2017. The company has a stock market value now of $6.3 billion and debt of $11.9 billion.

“This looks likes the first signs of capitulation perhaps in mining,” Paul Gait, a Sanford C. Bernstein Ltd. analyst in London, told Bloomberg Television. “Anglo used to be this big diversified South African conglomerate. It’s now selling 60 percent of its assets.”

Founded in 1917 by entrepreneur and philanthropist Ernest Oppenheimer, Anglo American was built on the back of South Africa’s giant gold mines. Moving into diamonds with control of De Beers after Oppenheimer was elected to the board in 1926 — it owns 85 percent of the company after selling it and then buying it back — and then adding platinum and coal, Anglo grew rich and powerful through much of the 20th century.

Under Ernest’s son, Harry, the company broadened its horizons. The company bought Hudson Bay Mining in Canada in 1961. The company went on to expand into steelmaking, timber and pulp and then copper in South America.

Minas Rio

More recently, it sought to expand into iron ore to join the companies feeding China’s seemingly insatiable need for steel.

Minas Rio was conceived by Cutifani’s predecessor during that bull run. It cost $5.1 billion to buy the project and $9 billion to build it. The price of iron ore, along with that of coal, diamonds, gold and most other things extracted from the ground, then sank.

Cutifani said it will struggle to make it into his list of “tier-one’’ mines, though the company will give it a chance to improve performance before a final decision on its future is made.

“How the mighty have fallen,” said Investec banker Wrathall, who worked underground in South African gold mines in the 1990s. “It’s shocking what has happened to such a great company.”