* Dollar index languishes near 3-1/2 week lows
* Pullback in U.S. 10-year yield weighs on dollar -analyst
* Commodity currencies remain firm, Aussie hits 2-month high
By Masayuki Kitano
SINGAPORE, Dec 28 (Reuters) - The dollar was on the defensive on Thursday, facing headwinds from a dip in U.S. 10-year bond yields, while commodity-linked currencies were bolstered by this week's rally in metal and oil prices.
The dollar's index against a basket of six major currencies last stood at 92.980 .DXY , languishing near Wednesday's trough of 92.956, its weakest level since Dec. 1.
"Bond yields have pulled back from their peaks and the dollar is trading with a soft tone," said Satoshi Okagawa, senior global markets analyst at Sumitomo Mitsui Banking Corporation in Singapore, referring to a pullback in U.S. 10-year Treasury yields.
The U.S. 10-year Treasury yield stood near 2.42 percent US10YT=RR , having come off a nine-month high of 2.504 percent set last week. The U.S. 10-year yield had slipped on Wednesday as investors rebalanced portfolios before year-end. euro edged up 0.1 percent to $1.1902 EUR= , having set a 3-1/2 week high of $1.1911 on Wednesday.
Against the yen, the dollar eased 0.2 percent to 113.19 yen JPY= , staying below a four-week high of 113.75 yen touched on Dec. 12.
Currencies of commodities exporters remained firm, in the wake of this week's rise in oil prices LCOc1 to 2-1/2 year highs and a surge in copper prices CMCU3 to four-year peaks.
The Australian dollar touched a fresh two-month high of $0.7780 AUD=D3 on Thursday, having gained 0.8 percent so far this week.
The Canadian dollar CAD=D3 last stood at C$1.2639. On Wednesday, the loonie had touched a three-week high of C$1.2627.
A rise to levels beyond its early December high of C$1.2624 would send the Canadian dollar to its highest since late October.