South32 has just made one of the biggest calls in its history, and it isn't a purchase. It's a sale. The mining group has agreed to sell almost its entire aluminium business — the smelters, refineries and mines, including the huge Hillside plant at Richards Bay — to the American producer Alcoa, in a deal worth up to R92 billion. In dollar terms the transaction is valued at up to US$5.6 billion. Under the agreement, Alcoa picks up South32's stakes right across the aluminium chain, from the Worsley refinery to the MRN bauxite mine to Hillside itself, leaving the miner with just one aluminium-family asset: the power-starved Mozal smelter in Mozambique, which has sat idle on care and maintenance since March.
Why the ratings agencies flinched
A R92 billion cash-in might sound like unambiguously good news, but Moody's didn't see it that way. The agency put South32's credit rating on review for a possible downgrade, warning that the sale would "materially reduce the company's scale, commodity diversification and operating footprint". In plain terms, it worried the miner would be left more exposed to a narrower set of metals. Investors wobbled too: the share price fell as much as 4.3% intraday on Friday before recovering to close down just 0.63% at R47.33, having jumped more than 11% earlier in the week when the Alcoa deal was first announced. The business Moody's is worried about losing is no small thing — in the year to end-June 2025, alumina and aluminium together made up roughly 60% of South32's underlying earnings, the cash-based profit measure miners lean on.
A new boss, a new direction
The timing has an extra twist. The deal landed on the same day that Matt Daley took over as chief executive from Graham Kerr, and Daley is wasting no time signalling where he wants to take the company: towards copper and zinc. He told Bloomberg the group has organic growth opportunities in those metals, with projects already nearing execution.
So the real question now isn't whether South32 can cash the Alcoa cheque. It's whether a leaner, copper-and-zinc miner can convince the market that smaller is smarter.
