SYDNEY -- Australia's largest mining companies say steel demand in China remains strong despite a slowdown and property crisis in the world's second-largest economy, with the price of iron ore holding up and delivering earnings largely in line with analysts' expectations. BHP, Rio Tinto and Fortescue, the three largest Australian-listed resource companies, released financial results this week, providing a snapshot of the iron ore market. Iron ore made up almost 70% of BHP's and Rio's underlying earnings before interest, taxes, depreciation, and amortization (EBITDA) for their respective reporting periods, and all of Fortescue's.