(Adds CEO, union, share price, details)
JOHANNESBURG, June 28 (Reuters) - AngloGold Ashanti is considering laying off 8,500 workers, some 30 percent of its workforce, Africa's biggest gold miner said on Wednesday, as it looks to restructure its South African mines.
"It is critical that we act to protect the long-term sustainability of this business and the majority of our workforce," Chief Executive Officer Srinivasan Venkatakrishnan, said in a statement.
It said its South African gold mining operations had experienced "heavy, and ultimately unsustainable, losses."
The company, which employs 28,000 people, said the potential lay-offs were part of its efforts to improve production and the cost base of its South African business.
In May, AngloGold reported a 16 percent drop in first-quarter profit following a decline in South African production and said it was reviewing its operations to restore margins and ensure their recovery.
AngloGold shares fell 3.44 percent to 133.41 rand by 1209 GMT.
Trade union Solidarity said it would work with the company to try to retain as many jobs as possible.
However, the union expressed concern about the potential for further job cuts across the sector due to new rules announced by the government to raise the minimum threshold for black ownership of mining companies to 30 percent from 26 percent. (Reporting by Tanisha Heiberg; editing by Jason Neely and Louise Heavens)