payments as a reduction of interest income on loans. The Company recorded a reduction of loan interest income related to these swap transactions of $2.8 million in the three months ended June 30, 2024, compared to a $1.7 million reduction of interest income in the three months ended June 30, 2023. The Company recorded a reduction of loan interest income related to these swap transactions of $5.5 million in the six months ended June 30, 2024, compared to a $1.7 million reduction of interest income in the the six months ended June 30, 2023. At June 30, 2024, the USD-Prime rate was 8.50% and the one-month USD-SOFR OIS rate was 5.33643%.
If market interest rates remain near their current levels, the Company’s interest rate swaps will continue to have a negative impact on net interest income.
Interest Income – Investments and Other Interest-earning Assets
Interest income on investments increased $364,000 in the three months ended June 30, 2024 compared to the three months ended June 30, 2023. Interest income increased $383,000 as a result of higher average interest rates from 2.86% during the three months ended June 30, 2023, to 3.09% during the three month period ended June 30, 2024. Partially offsetting that increase, interest income decreased $19,000 as a result of a decrease in average balances from $699.0 million during the three months ended June 30, 2023, to $696.2 million during the three months ended June 30, 2024. Average balances of securities decreased primarily due to normal monthly payments received related to the portfolio of U.S. Government agency mortgage-backed securities and collateralized mortgage obligations.
Interest income on investments increased $371,000 in the six months ended June 30, 2024 compared to the six months ended June 30, 2023. Interest income increased $663,000 as a result of higher average interest rates from 2.86% during the six months ended June 30, 2023, to 3.05% during the six month period ended June 30, 2024. Partially offsetting that increase, interest income decreased $292,000 as a result of a decrease in average balances from $702.9 million during the six months ended June 30, 2023, to $683.0 million during the six months ended June 30, 2024. Average balances of securities decreased primarily due to normal monthly payments received related to the portfolio of U.S. Government agency mortgage-backed securities and collateralized mortgage obligations. Proceeds from repayment of securities were generally used to fund loan growth and, to a limited extent, purchase additional securities.
Interest income on other interest-earning assets increased $92,000 in the three months ended June 30, 2024 compared to the three months ended June 30, 2023. Interest income increased $88,000 as a result of higher average interest rates from 4.93% during the three months ended June 30, 2023, to 5.31% during the three months ended June 30, 2024. Interest income increased $4,000 as a result of a slight increase in average balances from $97.0 million during the three months ended June 30, 2023, to $97.3 million during the three months ended June 30, 2024.
Interest income on other interest-earning assets increased $374,000 in the six months ended June 30, 2024 compared to the six months ended June 30, 2023. Interest income increased $263,000 as a result of higher average interest rates from 4.73% during the six months ended June 30, 2023, to 5.26% during the six months ended June 30, 2024. Interest income increased $111,000 as a result of an increase in average balances from $94.4 million during the six months ended June 30, 2023, to $98.9 million during the six months ended June 30, 2024.
Total Interest Expense
Total interest expense increased $8.6 million, or 33.9%, during the three months ended June 30, 2024, when compared with the three months ended June 30, 2023, due to an increase in interest expense on deposits of $6.0 million, or 27.5%, an increase in interest expense on short-term borrowings of $2.4 million, or 125.1%, an increase in interest expense on securities sold under reverse repurchase agreements of $173,000, or 78.3%, and an increase in interest expense on subordinated debentures issued to capital trusts of $28,000, or 6.6%.
Total interest expense increased $22.9 million, or 52.4%, during the six months ended June 30, 2024, when compared with the six months ended June 30, 2023, due to an increase in interest expense on deposits of $19.0 million, or 52.1%, an increase in interest expense on short-term borrowings of $3.7 million, or 99.2%, an increase in interest expense on securities sold under reverse repurchase agreements of $164,000, or 29.1%, and an increase in interest expense on subordinated debentures issued to capital trusts of $89,000, or 10.9%.
Interest Expense – Deposits
Interest expense on demand and savings deposits increased $2.8 million due to average rates of interest that increased from 1.25% in the three months ended June 30, 2023 to 1.76% in the three months ended June 30, 2024. Interest rates paid on demand deposits were