2023, as compared to $520,000 in net interest income for the same period a year ago. Combined, this component of net interest income contributed 16 basis points to net interest margin in the three-month period ended September 30, 2023, as compared to a seven basis point contribution for the same period of the prior fiscal year, and as compared to a 16 basis point contribution in the linked quarter ended June 30, 2023, when net interest margin was 3.60%.
For the three-month period ended September 30, 2023, our net interest rate spread, the difference between interest bearing assets and liabilities, was 2.92%, as compared to 3.46% in the year-ago period. The decrease in net interest rate spread, compared to the same period a year ago, resulted from a 171 basis point increase in the average cost of interest-bearing liabilities, compared to only an increase of 117 basis points in the average yield on interest-earning assets.
Interest Income. Total interest income for the three-month period ended September 30, 2023, was $58.1 million, an increase of $23.1 million, or 66%, as compared to the same period of the prior fiscal year. The increase was attributed to a 31.6% increase in the average balance of assets and by a 117 basis point increase in the average yield earned on interest-earning assets, as compared to the same period of the prior fiscal year. Increased average interest-earning balances were attributable primarily to growth in the loan portfolio, mortgage-backed securities, and other investment securities, partially offset by decreases in other interest-earning assets. The increase in interest-earning asset yield was attributable primarily to an increase in market interest rates.
Interest Expense. Total interest expense for the three-month period ended September 30, 2023, was $22.7 million, an increase of $16.2 million, or 250%, as compared to the same period of the prior fiscal year. The increase was attributable to a 171 basis point increase in the average cost of interest-bearing liabilities, combined with a 30.8% increase in the average balance of interest-bearing liabilities. The increase in the average cost of interest-bearing liabilities was attributable primarily to the increased rates paid on certificates of deposit, nonmaturity deposit accounts, and FHLB advances, while the increased average balance was attributable primarily to growth in interest-bearing nonmaturity deposit accounts, certificates of deposit, and FHLB advances.
Provision for Credit Losses. The PCL was $900,000 in the three-month period ended September 30, 2023, as compared to a PCL of $5.1 million in the same period of the prior fiscal year. The current period PCL was the result of a $1.6 million provision attributable to the ACL for loan balances outstanding, partially offset by a recovery of $670,000 in provision attributable to the allowance for off-balance sheet credit exposures. The Company’s assessment of the economic outlook at September 30, 2023, was little changed as compared to the assessment as of June 30, 2023. Qualitative adjustments in the Company’s ACL model were slightly decreased based on a reduced pace of loan growth. The Company increased adjustments related to classified hotel loans that have been slow to recover from the COVID-19 pandemic and modestly decreased the ACL attributable to other individually identified loans. As a percentage of average loans outstanding, the Company recorded net charge offs of 0.03% (annualized) during the current period, up slightly from the same period of the prior fiscal year. (See “Critical Accounting Policies”, “Allowance for Credit Loss Activity” and “Nonperforming Assets”).
Noninterest Income. Noninterest income for the three-month period ended September 30, 2023, was $5.9 million, an increase of $339,000, or 6.1%, as compared to the same period of the prior fiscal year. In the current period, increases in bank card interchange income, earnings on bank owned life insurance, and the addition of trust and wealth management services from the Citizens merger were partially offset by decreases in gains realized on the sale of residential real estate loans originated for that purpose, loan servicing fees, and other loan fees. Interchange revenue has increased as compared to the year ago period due to the increased customer base as a result of the Citizens merger. Fee income from the origination of residential real estate loans for sale on the secondary market was down 52% as compared to the year ago period, as both refinancing and purchase activity declined due to the increase in market interest rates, resulting in a decrease to both gains on sale of these loans and recognition of new mortgage servicing rights.
Noninterest Expense. Noninterest expense for the three-month period ended September 30, 2023, was $23.7 million, an increase of $6.8 million, or 40.1%, as compared to the same period of the prior fiscal year. In the current quarter, this increase in noninterest expense was attributable primarily to increases in compensation and benefits, data processing fees, occupancy expenses, other noninterest expenses, and intangible amortization expense. Charges attributable to merger activity totaled $134,000, as compared to $169,000 in the same quarter a year ago, and as compared to $829,000 in the fourth quarter of fiscal 2023, the linked quarter. The increase in compensation and benefits as compared to the