* Euro hits 1 mth low vs dlr, 3-wk low v yen as shares fall
* European equities tumble 1.8 percent; BoA results awaited
* Uncertainty over ECB steps, EZ economic worries dent euro
* Sterling, Aussie down 1.6 percent vs dollar as higher risk FX fall
(Recasts, adds quotes, updates prices)
By Jessica Mortimer
LONDON, April 20 (Reuters) - The euro slid to a one-month low against the dollar on Monday as sharp falls in equities sent investors back to the perceived security of the U.S. currency.
European equities tumbled 1.8 percent on caution before Bank of America earnings due later in the session.
This also sent the euro to a three-week low against the Japanese yen -- which typically gains during heightened risk aversion -- and weighed hard on currencies seen as high risk, with sterling and the Australian dollar both falling sharply.
Better-than-expected earnings from the likes of JP Morgan and Citigroup last week helped assuage concerns over U.S. banking sector health, but investors are still bracing for a raft of major U.S. bluechip earnings reports this week.
"Equity markets have turned down sharply and they are likely to be the key for currency markets today, along with the Bank of America results," CMC Markets analyst James Hughes said.
The euro was also under selling pressure as investors anticipated that the European Central Bank will cut rates next month and on uncertainty over what kind of additional unconventional policy measures they may announce.
The euro fell 0.6 percent against the dollar to a one-month low of $1.2953 and also hit a three-week low of 127.84 yen.
Among currencies seen as higher risk, the Australian dollar tumbled by 1.6 percent against its U.S. counterpart, hitting an 11-day low of $0.7087. Sterling also fell 1.6 percent to a low of $1.4559, its weakest in nearly 3 weeks.
At 0936 GMT, the dollar fell 0.4 percent against the yen to 98.72 yen.
ECB UNCERTAINTY
ECB President Jean-Claude Trichet signalled on Sunday that the bank was likely to cut interest rates by 25 basis points from their current 1.25 percent on May 7, though he gave no details of plans for further steps to stimulate the economy.
Further downbeat comments came from ECB Executive Board member Lorenzo Bini Smaghi, who warned against overstating the risks of deflation in an interview with the Financial Times Deutschland on Monday.
"There are worries about what the ECB will do, and also that they may have been too hesitant to introduce these measures," Frankfurt-based Commerzbank currency strategist Antje Praefcke said.
"We are also seeing some dollar strength due to the view that the U.S. may come out of the crisis first," she added.
Market players are keen to see whether the ECB will follow the Federal Reserve, the Bank of England and the Bank of Japan in making asset purchases to contain the financial crisis.
The single currency also remains under pressure due to concerns over the weakness of the euro zone economy just as the United States shows signs of recovery.
Monday is a quiet day for data, but investors will be watching the release of German ZEW and Ifo surveys, as well as euro zone purchasing managers' indices later in the week, where weak readings could further dent the euro.
(Reporting by Jessica Mortimer; Editing by Ruth Pitchford)