The benchmark S&P/ASX200 index rose 33.2 points, or 0.66 per cent, to 5,036.9 points, and the broader All Ordinaries index was up 32.7 points, or 0.65 per cent, at 5,057.2 points.
On the ASX 24, the March share price index futures contract was 38 points higher at 4,994 points, with 28,081 contracts traded.
OptionsXpress market analyst Ben Le Brun said investors had been looking forward to miner Rio Tinto's company earnings report, which was to be released after the market close.
"That is where we have seen a lot of the buying interest today," he said.
Rio Tinto was up $1.61, or 2.28 per cent, at $72.07 before it reported a $US2.99 billion annual net loss and underlying earnings down by 40 per cent to $US9 billion.
The financial results from engineering firm Downer EDI, and a Chinese investor taking a stake in aluminum producer Alumina also reverberated well among investors.
"After we got that Wesfarmers' number, that's when the ASX200 really started to make some inroads. So it's all looking pretty positive at this stage," Mr Le Brun said.
Global miner BHP Billiton jumped 97c to $38.89.
Aluminum producer Alumina was 9c, or 7.5 per cent, stronger at $1.29, after a large Chinese investor took a $452 million stake in the company.
Diversified conglomerate Wesfarmers improved 46c to $38.88, after it reported a nine per cent growth in first half profit, boosted by better earnings from supermarket operator Coles and home hardware supplier Bunnings.
Downer EDI surged 38c, or 7.82 per cent, to $5.24, after the engineering firm lifted its profit, resumed paying dividends, and said the $3.6 billion Waratah train project in NSW was now in very good shape.
Among other stocks, retailer David Jones lost 1c to $2.67 as its second quarter sales, which includes the vital Christmas period, fell 1.4 per cent.
Among the major banks, Commonwealth Bank shed 21c to $66.90, Westpac added 43c at $28.76, ANZ was 25c richer at $28.06, and National Australia Bank firmed 6c to $29.35.
The price of gold in Sydney was $US1,646.40 per fine ounce, down $US3.31 from $US1,649.71 on Wednesday.
National turnover was 1.87 billion securities worth $5.99 billion, with 519 stocks up, 495 down and 344 unchanged.
