SYDNEY, July 3 (Reuters) - Moody's Ratings said on Friday it placed Australian miner South32's S32.AX credit ratings on review for downgrade after it agreed to sell most of its aluminium assets to Alcoa AA.N for as much as $5.6 billion.

"The divestment would materially reduce the company's scale, commodity diversification and operating footprint, while removing assets that contributed around 37% of underlying earnings on average over the five fiscal years ended 2025," the ratings agency said.