* Oil deepens decline, takes focus away from central bank policies
* Dollar/yen hands back big chunk of gains made after BOJ easing
* Euro also benefits from risk aversion as US yields decline
* Canadian, Australian dollars on defensive as oil weakens
By Shinichi Saoshiro
TOKYO, Feb 3 (Reuters) - The yen and euro held on to overnight gains against the dollar on Wednesday after a sharp slide in crude oil prices fuelled risk aversion, driving down U.S. debt yields to 9-month lows and dulling the greenback's appeal.
The euro was steady at $1.0924 EUR= following an overnight gain of 0.3 percent. The dollar was little changed at 119.83 yen JPY= after shedding 0.9 percent overnight.
The U.S. currency had surged to a 6-week high of 121.70 yen on Friday after the Bank of Japan stunned the markets by adopting a negative interest rate policy.
But oil prices have since resumed declining, shaking equity markets and bringing investors' focus back to global growth woes and central bank policies.
"Since China growth concerns began shaking the markets in August, the broad theme has been central banks versus global risk," said Shin Kadota, chief Japan FX strategist at Barclays (L:BARC) in Tokyo.
"The yen benefited from the latest round of 'risk off'. The euro, which gained as U.S. yields fell, has also become a sort of safe-haven since August. I don't see China woes subsiding soon and the central bank versus global risk theme could play out indefinitely."
The latest drop in oil hit commodity currencies like the Canadian dollar, which had enjoyed several days of relief as global risk aversion had eased for a while after the BOJ's policy decision.
The Canadian dollar stood little changed at C$1.4051 to the dollar CAD=D4 following an overnight loss of 0.8 percent.
The Australian dollar, another commodity currency, was down 0.1 percent at $0.7033 AUD=D4 .
The Aussie is seen remaining on the defensive after sliding 1 percent on Tuesday when the Reserve Bank of Australia stood pat on monetary policy but left the door open to future easing.
U.S. crude CLc1 was on track for a third straight day of losses as hopes faded that major oil producers would agree to an output cut. O/R
The benchmark 10-year U.S. Treasury note yield US10YT=RR fell to 1.874 percent, lowest since April 2015. (Editing by Kim Coghill)