* Dollar buoyant with U.S. yields bouncing from 3-year lows
* Easing risk aversion weighs on yen, Swiss franc
* Graphic: World FX rates in 2019 http://tmsnrt.rs/2egbfVh
By Shinichi Saoshiro
TOKYO, Aug 20 (Reuters) - The dollar held near a three-weekhigh on Tuesday, as expectations global economies would unleashfresh stimulus and an improvement in appetite for riskier assetslifted yields on U.S. government bonds.
Yields on benchmark U.S. Treasuries pulled away fromthree-year lows as investors tip-toed back into riskier assets,lured by hopes for stimulus in major economies such as Germanyand China, which eased more recent global recession fears.
Investor focus on Tuesday will shift to the first setting ofChina's new lending benchmark under its recent interest ratereforms, due at 0130 GMT.
Risk appetite in global markets has been boosted this weekby the prospect of Germany ditching its balanced budget rule toboost spending and China's interest rate reform plan, which isexpected to lower corporate borrowing costs.
"The dollar is higher across the board, tracking the reboundin yields. The prospect of Germany embarking on stimulus was theturning point and the dollar has regained momentum since," saidYukio Ishizuki, senior currency strategist at Daiwa Securities.
The greenback traded little changed at 106.620 yenfollowing three straight sessions of gains, having moved awayfrom a seven-month low near 105.000 reached last week.
Against the Swiss franc, a currency sought in times ofmarket turmoil and political tensions along with the yen, thedollar hovered near a two-week high of 0.9820 francscaled overnight.
The euro was flat at $1.1081, caught near a two-week troughof $1.1066 set on Friday.
The Australian dollar dipped 0.1% to $0.6757against the broadly higher dollar.
Market focus will shift to the annual symposium of globalcentral bankers starting on Friday at Jackson Hole, Wyoming.
Particular focus will centre on Fed Chairman Jerome Powell'scomments on monetary policy at a time when investors widelyexpect the Fed to cut rates again at its next meeting inSeptember.
"A series of further rate cuts by the Fed has already beenpriced into the dollar. So the currency could gain a fresh boostif Powell does not sound as dovish as expected and clouds ratecut prospects," Ishizuki at Daiwa Securities said.(Reporting by Shinichi Saoshiro; Editing by Sam Holmes)