During the overnight session, the unit moved between $US0.6412 and $US0.6545.
Standard & Poor's lowered General Electric's credit rating from AAA to AA+ due to problems at the industrial conglomerate's lending arm, but raised its outlook for GE from negative to stable.
The ratings agency indicated another downgrade was unlikely.
Investors had concerns S&P would cut General Electric's rating further.
Bank of America said it, too, had been profitable in January and February, following news earlier in the week that Citigroup had operated profitably so far in 2009.
"We have been profitable for the first two months of the year," Bank of America chief executive Kenneth Lewis said.
Wall Street rose on the news.
The Dow Jones industrial average closed up 3.46 per cent, the S&P 500 index added 4.07 per cent and the Nasdaq composite index gained 3.97 per cent.
ANZ Banking Group senior markets dealer, Alex Sinton, said the positive sentiment on equity markets had boosted the dollar.
"The Dow is up, (and) that is certainly helping the equation," Mr Sinton said from Auckland.
"The GE rating was cut to only AA+, with people expecting it could have been cut further.
"That has been fairly bullish for things on the equity front."
With no local data due on Friday, Mr Sinton forecasts the dollar to trade between $US0.6495 and $US0.6560 in the Asian session.
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Dollar lower at noon
Share market has strong opening
