Results of Operations – Comparison of the three-month periods ended March 31, 2022 and 2021
General. Net income for the three-month period ended March 31, 2022, was $9.4 million, a decrease of $2.1 million, or 18.4%, as compared to the same period of the prior fiscal year. The decrease was attributable to increases in noninterest expense and PCL, partially offset by increases in net interest income and noninterest income, and by a decrease in provision for income taxes.
For the three-month period ended March 31, 2022, basic and fully-diluted net income per share available to common shareholders was $1.03 under both measures, as compared to $1.27 under both measures for the same period of the prior fiscal year, which represented a decrease of $0.24, or 18.9%. Our annualized return on average assets for the three-month period ended March 31, 2022, was 1.22%, as compared to 1.71% for the same period of the prior fiscal year. Our return on average common stockholders’ equity for the three-month period ended March 31, 2022, was 11.9%, as compared to 16.9% in the same period of the prior fiscal year.
Net Interest Income. Net interest income for the three-month period ended March 31, 2022, was $25.1 million, an increase of $2.0 million, or 8.5%, as compared to the same period of the prior fiscal year. The increase was attributable to a 14.8% increase in the average balance of interest-earning assets, partially offset by a decrease in net interest margin to 3.48% in the current three-month period, from 3.68% in the same period a year ago. As PPP loan forgiveness declined, the Company’s accelerated accretion of interest income from deferred origination fees on these loans was reduced to $180,000 in the current quarter, which added two basis points to the net interest margin, as compared to $1.2 million in the same quarter a year ago, which added 18 basis points to the net interest margin in that period. In the linked quarter, ended December 31, 2021, accelerated accretion of deferred PPP origination fees totaled $890,000, adding 13 basis points to the net interest margin. The remaining balance of deferred origination fees is significantly less than the amount accreted in recent quarters.
Loan discount accretion and deposit premium amortization related to the Company’s acquisitions dating back to 2014, including most notably the November 2018 acquisition of First Commercial Bank and the February 2022 acquisition of Fortune, resulted in $448,000 in net interest income for the three-month period ended March 31, 2022, as compared to $614,000 in net interest income for the same period a year ago. This component of net interest income contributed six basis points to net interest margin in the three-month period ended March 31, 2022, as compared to a contribution of ten basis points in the same period of the prior fiscal year, and a six basis point contribution in the linked quarter, ended December 31, 2021, when net interest margin was 3.77%.
For the three-month period ended March 31, 2022, our net interest rate spread was 3.37%, as compared to 3.54% in the year-ago period. The decrease in net interest rate spread, compared to the same period a year ago, resulted from a 39 basis point decrease in the average yield on interest-earning assets, partially offset by a 22 basis point decrease in the average cost of interest-bearing liabilities.
Interest Income. Total interest income for the three-month period ended March 31, 2022, was $28.3 million, an increase of $1.2 million, or 4.6%, as compared to the same period of the prior fiscal year. The increase was attributed to a 14.8% increase in the average balance of interest-earning assets, partially offset by a 39 basis point decrease 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, while average investment balances also increased, and average cash and equivalent balances increased at a modestly more substantial rate in percentage terms. The decrease in the average yield on interest-earning assets was attributable primarily to loans originated and renewed at lower market yields, adjustable-rate loans which re-priced at lower rates, the composition of our average interest-earning asset balances shifting to include a modestly higher proportion of cash and cash equivalents, as well as a reduced impact from accelerated accretion of interest income from deferred origination fees on PPP loans and accretable yield on acquired loan portfolios.
Interest Expense. Total interest expense for the three-month period ended March 31, 2022, was $3.2 million, a decrease of $726,000, or 18.4%, as compared to the same period of the prior fiscal year. The decrease was attributable to a 22 basis point decrease in the average cost of interest-bearing liabilities, partially offset by a 14.1% increase in the average balance of interest-bearing liabilities, as compared to the same period of the prior fiscal year. The decrease in the average