* Shares fall despite Anglo plans cut assets by 60 percent
* Aims to focus on diamonds, platinum, copper
* Investors concerned about debt
* Some predict rights issue, wider sales
By Olivia Kumwenda-Mtambo and Freya Berry
JOHANNESBURG/LONDON, Dec 10 (Reuters) - Anglo American's plans to shut or sell dozens of loss-making mines have failed to halt a dramatic slide in its share price and it may need to sacrifice stronger parts of the business or raise cash from shareholders to pay down its debt.
The company, which grew from gold fields near Johannesburg to dominate diamond, platinum and, to some extent, iron ore markets, is one of many miners struggling with a fall in commodities' prices driven by lower demand from China.
That makes selling assets that much harder.
Anglo's shares have slumped 11 percent since it announced the biggest restructuring in its nearly 100-year history on Tuesday, leaving it with a market value of $6.7 billion, down from $27 billion a year ago.
On Thursday, South Africa, which accounts for half its workforce, raised the alarm over the company's target of ending up with just 50,000 workers from 135,000 now, saying Anglo must make plans to save jobs and citing "national imperatives".
Bankers meanwhile were poring over its portfolio to see how it could raise the remaining $2 billion of the $4 billion it is seeking by the end of next year.
To survive the drop in commodities prices to multi-year lows, the mining group has already disposed of several non-core assets. This year it sold its stake in building materials company Lafarge Tarmac and two copper mines in Chile.
Its subsidiary Anglo American Platinum, the world's biggest platinum producer, also sold its labour-intensive South African Rustenburg mine.
Anglo also plans to sell some coal assets in Australia and South Africa, some copper mines and said it would press ahead with the sale of its phosphates and niobium businesses in 2016.
But more disposals were expected beyond 2016, a move that Anglo said would reduce its mines to not more than 25 from 55.
"The divestment programme may well be expanded to include better quality, but still 'non-core' assets," Credit Suisse analysts said in a note.
Analysts and bankers said Anglo could sell its stake in Cerrejon coal mine in Colombia, its stake in Samancor - a manganese joint venture with South32 - and a stake in Quellaveco greenfield copper project in Peru.
Anglo could also sell its Minas Rio iron ore mine in Brazil "if anyone is buying iron ore", a mining sector banker said.
Chief Executive Officer Mark Cutifani told investors on Tuesday Anglo would focus on its diamond, platinum and copper businesses as they offered better long-term potential.
Nickel, coal and iron ore would have to show ability to deliver cash or risk being taken out of the company's portfolio.
An Anglo American spokesman said on Wednesday the company would set out in February what its future portfolio would look like after selling and closing some mines.
Some analysts wondered if platinum would escape the cull.
"We are curious as to the likely fates of Minas Rio and Anglo American Platinum, given the supposed emphasis of the new strategy on cash generation," Shore Capital analysts said.
"We had previously perceived Anglo as the most likely of the diversified majors to go bust. The company is clearly determined to try to survive or go down fighting, but we will have to reserve judgement as to which is likelier for the time being."
A number of brokers downgraded the stock on Wednesday and Thursday amid concerns the new plan, which also involved suspending dividends, was only a short-term solution and that the company was not doing enough to lower its debt.
"The balance sheet concerns are likely to remain until commodity prices improve or net debt is reduced," UBS analysts said in a note.
Anglo American Finance Director Rene Medori said the company was not planning to tap the market for cash as of now. But several people in the market felt otherwise.
"The downside risk to commodity prices is still significant, and further action, including an equity issuance, may still be necessary in 2016," said Jefferies analysts, whose new 275p price target was lower than others.
Anglo started paring back in 2013 but Cutifani said the company had to take "bolder action" to focus on assets that would deliver cash flow throughout the economic cycle.
"How the market will respond will be a function of how quickly we can keep working the net debt down, which is an issue people are concerned about," Cutifani said.
Anglo forecasts its net debt for the end of 2015 unchanged at $13 billion-$13.5 billion and plans to lower it to less than $10 billion in the medium term.
That debt would make it hard to sell assets to private equity investors, some of whom have expressed willingness to make mining acquisitions in the absence of competition from within the struggling sector.
Platinum miner Lonmin was forced into a deeply discounted share issue in November to stay afloat, while mining and trading giant Glencore - which also suspended dividends and is selling assets - said on Thursday it was ahead of schedule with its plan to cut debt, signalling that turnarounds were possible. (Additional reporting by Alistair Smout in London; editing by Philippa Fletcher)