* Yen hits 5-mth low vs euro, tumbles vs Aussie
* ECB's Trichet: cenbank reluctant for rates to fall to 0%
* U.S. to put in $74-100 bln into toxic asset programme
By Charlotte Cooper
TOKYO, March 23 (Reuters) - The yen fell to its lowest in five months against the euro on Monday and dropped more than one percent against higher-yielding currencies as investors grew bolder on U.S. plans to tackle financial system problems.
Stock markets around Asia rose in anticipation of plans by Treasury Secretary Timothy Geithner to purge U.S. banks of "toxic" assets, leaving the yen, which had been a gainer last year in times of financial stress, at the mercy of the Australian and New Zealand dollars.
Geithner is set to speak at 1245 GMT but a U.S. official gave details of the plan beforehand, saying the government would put in $75 billion to $100 billion from its bailout fund to partner private investors and buy troubled assets at the heart of the financial crisis..
"It's naturally positive news for the financial markets. The scheme is necessary for the market, and the size of the reported toxic assets to be bought seems large," said Jun Kato, deputy general manager of treasury business group, Shinkin Central Bank.
Traders and analysts said that as well as improved risk appetite investors were favouring currencies whose central banks had interest rates above zero and looked unlikely to deploy forms of quantitative easing to get their economies moving.
An announcement by the Federal Reserve last week that it would buy up to $300 billion in longer-term government debt sent the dollar into a tailspin as investors fretted it would flood the market with dollars.
"The market doesn't want to buy currencies with central banks under quantitative easing. That leaves the euro as the easiest to buy," said a senior trader at a big Japanese bank.
The euro rose 1.3 percent to 131.63 yen, touching its highest since late October at 131.97 yen on trading platform EBS. Japan's markets were shut on Friday for a national holiday.
ECB WARY OF ZERO RATES
European Central Bank chief Jean-Claude Trichet signalled that the central bank remained wary of interest rates fallin, hitting its strongest since early January. Australia's key cash rate is a record low 3.25 percent.
The Fed's decision last week saw the dollar notch up its steepest weekly fall since 1985 against a basket of currencies.
The dollar firmed 0.4 percent to 96.35 yen, but was still well down from a four-month high of 99.69 hit earlier in March. It dropped to a one-month low of 93.55 last week.
The euro gained 0.7 percent to $1.3666, after hitting a 2-½ month high at $1.3739 on EBS last week.
"The basic direction for the dollar is the downside still," said Masafumi Yamamoto, head of FX strategy Japan at Royal Bank of Scotland.
"We have seen some rebound on Friday so it's not a one-way street. But the dollar remains heavy."
President Barack Obama said in a television interview that the dollar was still strong but warned that excessive borrowing and high deficits could weaken demand for U.S. Treasury bills. (Additional reporting by Satomi Noguchi; Editing by Michael Watson)