Ten-year notes rose 5/32 in price to yield roughly 1.603 percent, down 2 basis points from late US trade on Tuesday.

China's official purchasing managers' index for the services sector fell to 53.7 in September, the lowest point since November 2010, according to the latest survey from the National Bureau of Statistics.

That survey result seemed to give a slight lift to Treasuries, said a portfolio manager for a major Japanese bank in Tokyo. He added, however, that trading volumes were light.

The 10-year Treasury yield will probably trade in a range of roughly 1.5 percent to 1.8 percent until the year-end, the portfolio manager added.

"Although we need to keep an eye on the impact from monetary policy, there have been many signs that point to an economic slowdown," he said.

There is uncertainty about how effective the Federal Reserve's aggressive monetary stimulus will be in supporting economic growth, he added.

The 10-year Treasury yield had hit a four-month high of 1.894 percent in mid-September, as inflation expectations and equities rose after the Fed unveiled an open-ended programme to buy $40 billion in mortgage-backed securities each month.

Such moves have since faded, however, and the 10-year yield is now down about 29 basis points from that peak.