* Fresh uncertainty towards French elections adds to risk aversion
* Yen hits five-month highs vs dollar, euro, sterling and Aussie
* Graphic: World FX rates in 2017 tmsnrt.rs/2egbfVh
By Jemima Kelly
LONDON, April 12 (Reuters) - The yen hit five-month highs against the dollar, euro and sterling on Wednesday, as simmering geopolitical tensions checked risk appetite and put the safe-haven Japanese currency in favour.
Investors' flight-to-safety underpinned traditional safe-havens like the yen, U.S. Treasuries and gold, amid fresh worries over France's presidential election, and possible U.S. military action against Syria and North Korea.
"It cannot come as a surprise that the financial markets are fully focused on political developments and investors are increasingly looking for safe havens as a result," wrote Commerzbank currency strategists in a research note. "In the FX markets it is mainly the Japanese yen that is benefitting from this development - not exactly a major surprise."
"What is more surprising is that the dollar, which is usually in demand in uncertain times, has not been able to appreciate. That is probably mainly due to the fact that the United States is at the centre of these geopolitical risks."
The dollar fell on Tuesday and added to those losses on Wednesday, edging down 0.1 percent against a basket of major currencies to 100.62.
North Korean state media threatened a nuclear attack on the United States at any sign of American aggression on Tuesday, while U.S. President Donald Trump tweeted that Pyongyang was "looking for trouble" and the United States would "solve the problem" with or without China's help.
Trump's administration also accused Russia of trying to shield Syria's government from blame for a deadly gas attack, as Secretary of State Rex Tillerson brought a Western message to Moscow condemning its support for President Bashar al-Assad.
The Japanese currency had gained over 1 percent on Tuesday, with the dollar falling below 110 yen for the first time since mid-November, and it extended those gains on Wednesday, trading as strongly as 109.35 yen to the dollar in Asian trade.
In European trade it had come off those highs but was still up 0.1 percent on the day, at 109.625.
It was a little down against the euro after earlier hitting 115.91.
"There was a lot of bids and option barriers lined up around 110 yen, so a breach of this level shows how widespread the latest dollar selling was," said Junichi Ishikawa, senior forex strategist at IG Securities in Tokyo.
"The yen's gains against the euro also bears watching, with uncertainty towards the French presidential elections clearly the driving factor."
And in a new twist to the French elections, a far-left veteran who had been written off as a long shot has now surged into the top four, pushing some pollsters to calculate the most extreme runoff scenarios.
The euro edged up against a struggling dollar to $1.0617 .
For Reuters Live Markets blog on European and UK stock markets see reuters://realtime/verb=Open/url=http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageId=livemarkets
Reporting by Jemima Kelly; Editing by Andrew Heavens