Fortescue's first-half profit after tax was $4.08 billion, up from $2.45 billion a year earlier. This was in line with a consensus of $4.09 billion from 10 analysts compiled by research firm Vuma Financial.
Industrial stocks were also lower, with airport operator Auckland International Airport Ltd and construction services provider CIMIC Group Ltd down 1.4% and 3.3%, respectively.
"Throughout the collaboration the two companies will also share knowledge on reducing carbon emissions across the steel value chain," a statement from BHP said.
The S&P/ASX 200 index was up 1.1% at 6,725.70 by 2350 GMT, its best session since Jan. 19, after ending about 2% lower on Thursday. But it was on track to rise 1.7% in January, its fourth straight monthly gain.
Fortescue is also undertaking a detailed review of construction costs at its $2.6 billion iron bridge project, which is due to produce first ore in the first-half of 2022.
Burberry jumped 3.5% as underlying sales fell 9% in the three months ended December, but the company said it remained confident in the future, buoyed by sales growth of 11% in Asia-Pacific stores.
Brazilian iron ore miner Vale SA said on Wednesday its Samarco joint venture with BHP had begun the gradual restart of operations, after a deadly dam failure in 2015.
New South Wales maintained a steady downward trend in COVID-19 cases as it attempts to contain an outbreak in capital Sydney, reporting nine fresh local infections versus eight on Wednesday.
Tech stocks continued their winning streak, closing at a record level. Afterpay was the biggest gainer in the index, marking a record closing level for the fourth session in a row.