The government's sale US$35 billion of two-year debt drew a yield of 0.295 per cent, compared with a forecast of 0.304 per cent in a Bloomberg News survey of seven of the Federal Reserve's 21 primary dealers, while the bid-to-cover ratio was 4.02, compared with an average of 3.73 for the past 10 sales.
Meanwhile, Apple unveiled its latest product, the new iPad mini as well as refreshed desktop and laptop computers. Its shares were last 1.3 per cent lower. The new iPad will go on sale early next month.
As the Fed's policy committee started a two-day meeting today, the New York Times reported that central bank chief Ben Bernanke has told close friends he probably will not seek a third term even if US President Barack Obama wins a second term in the November 6 election.
In Europe, the Stoxx 600 Index finished the session with a 1.7 per cent drop from the previous close. National benchmark stock indexes also fell in the UK, Germany and France, closing with losses of 1.4 per cent, 2.1 per cent and 2.2 per cent respectively.
The mood remains lacklustre among consumers. An index of household sentiment in the euro zone barely budged in October, advancing to minus 25.6 from minus 25.9 in September, according to European Commission initial estimate data. Last month's reading was the worst since May 2009.
Separate data showed that Spain's economy shrank for a fifth consecutive quarter. And Moody's slashed its credit rating on five Spanish regions including Catalonia.