Stocks to watch on the Australian stock exchange:

API – AUSTRALIAN PHARMACEUTICAL INDUSTRIES – down 4 cents, or 2.7 per cent, at $1.465

The pharmacies operator and health and beauty products retailer’s half year profit dropped 14 per cent, and it said it will continue to expand its Priceline Pharmacy network.

BHP – BHP BILLITON – up 87 cents, or 2.9 per cent, at $30.94

The mining giant has trimmed its full-year iron ore production guidance due to unexpected dumper car maintenance.

EVN – EVOLUTION MINING – up 2.5 cents, or 0.8 per cent, at $3.355

The gold miner has improved its full year production forecast after reporting a lift in production in the March quarter.

S32 – SOUTH32 – up 18.5 cents, or 4.9 per cent, at $3.895

The diversified miner has lowered its full year coal production guidance as it carries out work aimed at returning annual production at Illawarra Metallurgical Coal to historical rates, and improved its production forecasts for manganese.

STO – SANTOS – down 3.5 cents, or 0.6 per cent, at $5.945

Santos has lowered its full-year production and sales guidance due to the shutdown caused by February’s magnitude 7.5 earthquake in Papua New Guinea.

SUN – SUNCORP – up 5 cents, or 0.4 per cent, at $13.75

Suncorp chairman Ziggy Switkowski will retire from the board of the financial services firm in September and be replaced by director Christine McLoughlin.