Mo. Rev. Stat. § 110.200

If the bids submitted under the provisions of section 110.140 shall not, when taken together, include the whole of said funds, the county commission may let the part or parts not bid for in the manner provided in section 110.190, or, if the rate of interest offered upon any part or parts into which said funds are divided shall, in the judgment of the commission, be too low, said county commission may accept one or more bids for one or more of said parts, and readvertise and relet the part or parts of said funds for which an adequate rate of interest has not been offered, or may let such part or parts in the manner provided in section 110.180.