* Euro falls; hits 1 mth low vs dlr, 3-wk low vs yen

* Trichet signals rate cut, no details on further measures

* Uncertainty over ECB steps, EZ economic worries dent euro

(Updates prices, changes byline, dateline; previous TOKYO)

By Jessica Mortimer

LONDON, April 20 (Reuters) - The euro fell against the dollar and the yen on Monday on uncertainties over the next policy steps the European Central Bank will take to stimulate the economy.

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, but gave no details of plans for unconventional measures. [ID:nT138276]

Uncertainty over what form these measures will take, coupled with concerns the euro zone economy remains weak while the U.S. shows signs of recovery, earlier pushed the euro to a one-month low against the dollar and a three-week low versus the yen.

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.