* Asia ex-Japan stocks set for weekly loss; Nikkei higher
* Euro falls back from three-week high amid French election fears
* Gap between French, German Treasury yields widens
* Wall Street posts gains on rising earnings expectations
By Nichola Saminather
SINGAPORE, April 21 (Reuters) - Asian stocks rose, lifted by bets on strong U.S. earnings and U.S. tax reform, while the euro retreated from a three-week high as jitters returned over the first round of French presidential elections on Sunday after a shooting in Paris.
MSCI's broadest index of Asia-Pacific shares outside Japan added 0.25 percent. It is set to end the week 0.6 percent lower.
Japan's Nikkei advanced 0.8 percent, on track for a weekly gain of 1.3 percent.
The euro was marginally higher at $1.07185 early on Friday. On Thursday, it jumped to 1.0778, its highest level since March 29, and French stocks jumped by 1.5 percent after polls showed French centrist Emmanuel Macron easily beating far-right, anti-European Union candidate Marine Le Pen in the second round on May 7.
But the euro fell back to close only slightly higher after a shooting on the Champs-Elysees shopping boulevard, in which one policeman was killed and two others were wounded. Islamic State claimed responsibility for the attack, according to the group's Amaq news agency.
"Euro bulls will definitely respond to positive news around Macron, but that dissipates as the reality of low turnouts sets in," said Alfonso Esparza, senior currency analyst at OANDA in Toronto.
"Everybody remembers the Brexit polls and even the U.S. election polls. After those misses it is going to take a lot to make the markets trust them again."
French 10-year Treasury yields slumped to a three-month low of 0.856 percent on Thursday, while safe-haven German bund yields jumped to 0.244 percent, their highest close in two weeks.
Markets are awaiting several economic indicators from Europe later in the session, including Eurozone manufacturing and services figures for April and British retail sales for March, to be followed by U.S. manufacturing and services data for April and existing home sales for March.
Wall Street indexes closed between 0.75 percent and 0.9 percent higher on rising expectations for first-quarter corporate profits. S&P 500 stock index company earnings now are expected to have gained 11.1 percent in the first quarter.
The dollar retained Thursday's 0.4 percent gain, trading flat at 109.34 yen. It is up 0.7 percent for the week.
The dollar index, which tracks the greenback against a basket of trade-weighted peers, was also steady at 99.816, on track to lose 0.7 percent this week.
In commodities, oil was stronger on Friday following Thursday's choppy session as a tussle continued between worries over rising U.S. production and optimism over comments from leading Gulf oil producers that an extension to OPEC-led supply cuts was likely.
U.S. oil jumped 1.1 percent to $50.83 a barrel early on Friday, its biggest one-day gain in almost two weeks, shrinking losses for the week to 4.4 percent.
Gold was also little changed on Friday at $1,280.61 an ounce, holding on to most of Thursday's 0.2 percent gain as investors remained hesitant ahead of the French election. It is poised for a weekly loss of 0.35 percent. (Reporting by Nichola Saminather; Additional reporting by Sadiq Iqbal Ahmed; Editing by Eric Meijer)