Among Australian-listed companies, BHP Billiton's ration outlook was changed to positive from stable by Moody's Investors Service on Wednesday, while keeping the A3 rating unchanged.
"The change in outlook to positive reflects our expectation that BHP Billiton will continue to generate material earnings and solid free cash flow in the current environment," Matthew Moore, a senior credit officer at Moody's said in a statement.
"This will allow the group to maintain strong margins and credit metrics for its ratings over the next 12-18 months, despite our expectations for lower commodity prices."
BHP shares ended down 2.31 percent, swept in a downdraft among Australian resources plays.
Rio Tinto was down 0.95 percent, Alacer Gold was off 3.35 percent and Woodside shed 0.50 percent.
Declines in banking shares also weighed the Australian market.
ANZ fell 2.79 percent after reporting lower-than-expected earnings on Tuesday, with fiscal first-half profit coming in at A$3.41 billion, compared with expectations for A$3.49 billion, according to Reuters.
In a note Tuesday, Citi said the Australian division weighed on results as retail banking suffered from a management decision to pull back from the mortgage market amid intense competition.
Among peers, CBA fell 1.70 percent and NAB lost 2.71 percent.
Shares of Australia-listed telecom Vocus plunged 27.16 percent to end at A$2.44 after the company cut its earnings outlook for fiscal 2017, saying it expected earnings before interest, tax, depreciation and amortization (Ebitda) at $365 million to $375 million, compared with previous guidance of $430 million to $450 million. That followed an accounting review of when to recognize revenue as well as lower forecast billings and an increase in service delivery headcount.
Citi cut shares of Vocus to Neutral from Buy and slashed its target price to A$3.40 from A$6.00 in a note on Tuesday.
"With revenue falling short of expectations and operating costs rising, we no longer have confidence that Vocus will be able to deliver on the full potential of its recently combined businesses," Citi said.
But it added that it didn't cut the shares to sell because while the company "clearly faces some serious challenges," its underlying assets are valuable and the stock has already dropped significantly.
In Singapore, the heavily weighted banking shares were sharply higher in late afternoon trade.
DBS jumped 4.88 percent after reporting on Tuesday better-than-expected first quarter net profit of 1.21 billion Singapore dollars, up 1 percent on-year, above the S$1.09 billion forecast in a Reuters poll.
Peers UOB and OCBC advanced 1.93 percent and 2.0 percent respectively in afternoon trade.
In the currency markets, the U.S. dollar index, which measures the greenback against a basket of currencies, was at 99.064 at 2:49 p.m. HK/SIN.
The dollar fetched 112.05 yen at 2:49 p.m. HK/SIN, down from highs around 112.30 yen overnight.
U.S. equities closed mostly flat on Tuesday. The Nasdaq composite hit an intraday record of 6,102.72 and eked out a closing record, with shares of Apple also hitting a new high.
Apple's stock also had the most positive impact on the Nasdaq 100 index, which also reached a record high ahead of the results.