By Hideyuki Sano
TOKYO (Reuters) - The dollar dipped against riskier currencies on Tuesday as hopes for a COVID-19 vaccine and big corporate deals improved investor appetite for assets such as the yuan and the euro.
The dollar index (=USD) dipped to 93.029, slipping further from a one-month high of 93.664 touched last Wednesday, with its low last week of 92.695 seen as an immediate support.
The euro inched up to $1.1867 (EUR=), having gained for four straight sessions until Monday.
Against the safe-haven yen, the dollar traded at 105.73 yen
Helping sentiment, AstraZeneca (L:AZN) resumed British clinical trials of its COVID-19 vaccine, one of the most advanced in development while Pfizer Inc (N:PFE) and BioNTech SE (F:22UAy) proposed expanding their Phase 3 COVID-19 vaccine trial.
"It was uplifting that Pfizer has made clear a target of vaccines. As risk assets bounced back, the dollar has lost momentum," said Kyosuke Suzuki, director of forex at Societe Generale (OTC:SCGLY).
Wall Street shares bounced back also as several multi-billion dollar deals -- including Nvidia's (O:NVDA) purchase of chip designer Arm and a deal between Oracle (N:ORCL) and China's ByteDance on TikTok -- lifted confidence.
The British pound bounced back to $1.2851
Still, traders said the currency looks vulnerable as the EU warns British Prime Minister Boris Johnson's bill would collapse trade talks and propel the United Kingdom towards a messy Brexit.
Elsewhere, the offshore Chinese yuan hit a 16-month high of 6.8053 yuan per dollar on Monday and last traded at 6.8098
China's retail sales and industrial output data for August due later in the day is its immediate focus.
The yuan's strength helped to lift MSCI emerging market currency index (MIEM00000CUS) to a six-month high.
The Australian dollar slipped 0.2% to $0.7270
Traders also look to central bank policy meetings in the United States on Wednesday and in Japan and Britain on Thursday.
In particular, this week's Federal Reserve meeting will be its first since Chairman Jerome Powell unveiled a shift toward greater tolerance of inflation, effectively pledging to keep interest rates low for longer.
Projections from Fed policymakers that inflation will remain below 2% in their economic forecasts, to be extended to 2023 this time, could strengthen expectations that interest rates will stay low for a long period of time, analysts say.