Perth-based iron ore miner Portman Ltd has increased its iron ore prices, following Rio Tinto Ltd's new deal with Baosteel, as it falls short of its $241 million off-market share buy-back.

Perth-based iron ore miner Portman Ltd has increased its iron ore prices, following Rio Tinto Ltd's new deal with Baosteel, as it falls short of its $241 million off-market share buy-back.