SYDNEY - The US dollar stayed under pressure on Monday in the wake of disappointing first-quarter U.S economic growth, leaving the yen, sterling and even high-beta currencies like the Australian dollar at multi-week highs.

The dollar fell as low as 80.25 yen (S$1.24), plumbing depths not seen since late February. It last stood at 80.34. Sterling bought US$1.6276  (S$2.01), having scaled an eight-month peak of US$1.6280 on Friday.

Trading in Asia is likely to be subdued though with Japan closed for a public holiday. Most of Asia will be shut on Tuesday for the May Day holiday.

Data on Friday showed US economic growth cooled in the first quarter partly as businesses cut back on investment, bolstering the Federal Reserve's case that interest rates should be kept near zero at least though late 2014.

While the slowdown was not bad enough to spur more bond buying, or quantitative easing (QE), it should keep alive market expectations for such a move.

"The US GDP was a bit on the soft side and all eyes are now be fixed on the upcoming labour release (on Friday). A flavour of QE is back in the air, driving the USD lower and risky assets higher," said Sebastien Galy, strategist at Societe Generale.

That would also go some way in explaining why sterling has outperformed the greenback, despite Britain's double-dip recession. In fact, sterling's fortunes appeared to have turned a corner and currency speculators are now betting on further gains.

The dollar lost quite a bit of ground against the Australian dollar even as the market is expecting an interest rate cut by the Reserve Bank of Australia on Tuesday.

The Aussie stood at US$1.0455, not far off a four-week high of US$1.0475 set on Friday.

All 22 economists polled by Reuters on Friday expected a rate cut, with one believing the RBA will go as far as a 50 basis-point easing.

"The case to cut rates is overwhelming: economic growth is running below trend; key sectors of the economy such as retailing, housing and manufacturing are really struggling; the jobs market is weak; and underlying inflation is at the low end of the 2 to 3 per cent target range," said Shane Oliver, head of investment strategy at AMP Capital Markets.

"While the absence of a major crisis probably means the RBA will stick to a 0.25 percentage point cut, it should be cutting by 0.5 points."

The dollar didn't fare too badly against the euro, which has its own problems especially after last week's surprise credit rating downgrade of Spain by Standard & Poor's.

The single currency briefly touched a three-week high of US$1.3270 on Friday and last stood at US$1.3240. It was still stuck in a US$1.3000/1.3385 range seen this month.

Traders said a key test for the markets is the outcome of a Spanish bond sale on Thursday, where Madrid is looking to raise an estimated 3 billion euros.