In the same sale, the yield on the 182-day Treasury bill also rose to 11.020 percent from 10.811 percent last week, the bank said.
The bank raised a total of 13.86 billion shillings ($136.82 million), against a target of 12.0 billion shillings, after investors offered bids worth more than it sought.
Next week, the bank will offer Treasuries of all maturities worth a total of 16 billion shillings, it said.