The benchmark weighted-average seven-day bond repurchase rate fell 14.31 basis points to 3.2033 percent at midday, from 3.3464 percent at the close on Tuesday.
The 14-day repo rate crept up to 3.4676 percent from 3.4448 percent, marking its higest level this month, but still below its 28-day moving average.
Traders said that rates were at a relatively stable level and that the day's movements were simply a matter of correcting slight imbalances.
Looking at 28-day moving averages supports this case -- overnight and 14-day rates had been below their month average and so were due a rise, while the 7-day had crept above the average in Tuesday's trading.
A trader at an Asian bank in Shanghai added that short-term money supply was already ample, making it difficult for banks to lend, while longer-term tenors were tight ahead of an annual spike in cash demand at the year-end.
The one-day repo rate rose slightly to 2.3123 percent from 2.2543 percent while the 28-day tenor rose to 3.8529 percent from 3.6906 percent.
After Tuesday's 114 billion yuan ($18.29 billion) injection through reverse repos, market participants expect the central bank to roughly balance fund injections and drains for the week.
Maturing reverse repos and bills are set to drain a net 227 billion yuan from the system, meaning the central bank would need to inject the same amount to strike a balance.