TOKYO, April 22, 2009 (AFP) - The euro was weaker in Asian trade Wednesday as investors sold risky assets while awaiting the results of Washington's "stress tests" of the viability of top US banks.

The yen climbed against its major rivals on safe-haven demand as Tokyo shares staged a lacklustre performance despite overnight gains on Wall Street. The euro declined to 1.2944 US dollars ($1.95) in Tokyo afternoon trade from 1.2950 US dollars in New York late Tuesday, and to 127.45 yen ($1.95) from 127.81. The US dollar fell to 98.44 yen from 98.69.

Investors were waiting for the results of Washington's tests of the health of the top 19 US banks, analysts said.

"US investors became more cautious in taking risks, repatriating some of their investments in the euro," said Hiroshi Sakurai, currency analyst at Mizuho Investors Securities.

The euro had risen on Tuesday after Germany's ZEW economic sentiment index posted its first positive reading since July 2007, pointing to a possible pickup in the eurozone's largest economy in the second half of 2009.

In recent months, the US dollar and yen have benefited from so-called "risk aversion" during times of market turmoil, while the euro is seen as more vulnerable to the economic downturn.

"Investor risk appetite won't return until early May when the results of the stress tests come out," Sakurai said.

A US blog said leaked results of the stress tests showed 16 of the 19 banks are "technically insolvent," though this was denied by the US Treasury. But dealers said this was also affecting sentiment.

The market appeared to shrug off Japanese trade data suggesting that an export slump eased in March, even though overseas demand remained very weak. Instead safe-haven flows were seen as boosting the yen.

"Risk aversion spread and encouraged more yen buying," Osao Iizuka, head of forex trading at Sumitomo Trust & Banking, told Dow Jones Newswires.

Against Asian currencies, the dollar declined to $1.5072 from 1.5084 a day earlier, to 33.83 Taiwan dollars ($1.51) from 33.89 and to 10,840 Indonesian rupiah ($1.51) from 10,845.

The greenback fell to 35.56 Thai baht ($1.50) from 35.62 but climbed to 1,348.15 South Korean won ($1.48) from 1,347.45 and to 48.50 Philippine pesos ($1.51) from 48.31.