* Euro at 5-mth low vs dlr; breaks thru 200-day moving avg
* Greek woes hurt euro; U.S. senate election helps dollar
* China lending curbs weighs on commodity currencies (Adds details, comment updates prices, changes byline)
By Steven C. Johnson
NEW YORK, Jan 20 (Reuters) - The euro fell to a five-month low against the dollar on Wednesday amid worries about Greece's ability to finance its deficit, while fear that China is trying to slow bank lending dulled demand for commodity currencies.
Analysts said the dollar also rose on hopes that the Republican upset victory for the vacant U.S. Senate seat from Massachusetts will force Congress to rein in the fiscal deficit.
"The momentum clearly favors the dollar right now, and the market seems willing to latch onto any reason to buy it," said Matthew Strauss, senior currency strategist at RBC Capital Markets in Toronto.
He said reports that Chinese banks were told to curb lending weighed on commodity currencies such as the Australian dollar and boosted the greenback. Tighter policy may slow China's recovery and cut demand for commodities, analysts said.
Wall Street suffered its worst slide of the new year on the news, while the dollar and yen rose as investors who used the currencies to fund other trades were forced to buy them back. The Australian dollar shed 1.8 percent to $0.9077.
The euro last changed hands at $1.4105, down 1.4 percent, after earlier hitting $1.4081, a five-month low. Euro losses gained speed after it traded below its 200-day moving average, which was important support against the dollar.
The euro fell 1.2 percent to 128.68 yen, its lowest level in a month, and the dollar rose 0.1 percent to 91.22 yen. The dollar gained 1.2 percent to 1.0442 Swiss francs. CHF=> The euro fell as low as 86.52 pence, its weakest since late August.
Analysts said worries about cash-strapped Greece's finances battered the currency on Wednesday as borrowing costs for the troubled euro zone country surged and the Greek government said it was considering all options to raise funds, including selling bonds directly to the public.
Greece's ballooning budget deficit, which hit 12.7 percent of gross domestic product in 2009, has sparked one of the worst fiscal crises in the euro zone since the euro was introduced.
Meanwhile, analysts said Tuesday's Massachusetts election result could force legislative compromises in the Senate that would put the brakes on fiscal spending.
The U.S. budget deficit swelled to a record $1.4 trillion last year, largely due to the hundreds of billions spent to reignite the U.S. economy after a financial crisis.
"Euro/dollar will stay under selling pressure at least in the near term," said Paul Mackel, director of currency strategy at HSBC in London. "If the market is considering whether the U.S. fiscal outlook is looking better while it's still looking (shaky) in the euro zone, that's giving conviction to be short on the euro."
Currencies from commodity producers, which depend on raw material exports for income, fell after Chinese media said banks were being told to curb lending. Australia's dollar fell 1.8 percent to $0.9077.
The New Zealand dollar shed 2.8 percent to $0.7185, hurt by the Chinese reports and by tame inflation data that weakened the case for an imminent interest rate hike.
Weaker-than-forecast Canadian inflation data knocked the Canadian dollar to a two-week low of C$1.0490 per U.S. dollar. It was last at C$1.4074 per greenback.