South32 boss Graham Kerr says he is happy for his business to be "predictable", as the diversified mid-tier miner unveiled a 17 per cent profit jump for the December half and a special dividend that was not a shock, but was welcomed by investors.

Mr Kerr said good cost control for the December half, strong performance across its operations and higher commodity prices combined to help South32 record a strong profit rise.

"I think the base business overall is running well, and that's reflected by the fact that the majority of our operations easily hit their target for the period in terms of production," he said.

South32 reported a December half profit after tax of $US635 million, up from $US543 million in the prior corresponding period.

The company declared a fully franked interim dividend of US5.1 cents per share, and a special dividend of US1.7 cents per share. The dividend will be paid on April 4.

"Having established a strong track record, we will continue to return any excess capital to shareholders in a timely and efficient manner," he said.

Shares in South32 rose 3.5 per cent to close at $3.80, its highest closing price in 2019.