(Adds analysis, quotes, stocks on the move)
By Ian Chua and Gyles Beckford
SYDNEY/WELLINGTON, Aug 20 (Reuters) - Australian shares fell to their lowest in seven months on Thursday following slides across global markets that saw major banks and miners all come under pressure, outweighing upbeat earnings from Qantas Airways and other companies.
The S&P/ASX 200 index .AXJO shed 1.4 percent, or 75.6 points, to 5,304.6 by 0307 GMT. It fell as far as 5,296.1, a low last seen in late January.
The big four banks were led by a 2.4 percent fall in Commonwealth Bank CBA.AX , while mining giants BHP Billiton (LONDON:BLT) BHP.AX and Rio Tinto (LONDON:RIO) RIO.AX were both down more than 2 percent.
Among energy stocks, oil and gas producer Woodside Petroleum WPL.AX plumbed a three-year low of A$31.43 as U.S. crude struggled at 6-1/2 year lows.
Even Qantas, which reported a return to profit, was not spared. Shares in the airline were down 1.1 percent in afternoon trade, a big turnaround from a seven-year peak of A$3.90 reached earlier following a 3.7 percent gain.
The broad selloff came after U.S. and European stocks fell overnight amid ongoing worries about slowing Chinese growth and uncertainty about when the Federal Reserve will hike interest rates.
"Clearly there are growth fears out of China and issues around if and when and how and what will happen with the Fed," said Evan Lucas, market strategist at IG. "There are also issues around the oil price and what is going on with copper. Just general uncertainty and that's what is feeding through."
New Zealand stocks were also lower with the benchmark NZX50 share index shedding 0.2 percent, or 12.9 points, to 5,737.1.
Among leading stocks, telecommunications company Spark was down 2.0 percent ahead of Friday's results announcement.
Specialised milk producer A2 Milk slumped 9.1 percent to a one-month low after reporting a loss on one off costs but a lift in operating earnings. It also said it had heard nothing from potential bidders after rebuffing them last month.
In contrast, online auction and market operator Trade Me rallied 4.2 percent as it reported a flat profit but said it expected earnings growth in the coming year.
Rubber goods manufacturer Skellerup climbed 5.9 percent to a one-month high after reporting a 6 percent rise in profit and forecast earnings growth.
(Editing by Richard Borsuk)