Net interest income after provision for loan losses increased $243,000, or 7.7%, for the six months ended June 30, 2021 to $3.4 million as compared to $3.2 million for the six-month period ended June 30, 2020. Total interest income decreased $4,000, or 0.1%, when comparing the two periods, due to a decrease in the yield earned on interest-earning assets partially offset by an increase in the average balance of interest-earning assets. The average tax equivalent yield on interest-earning assets decreased to 3.38% for the six months ended June 30, 2021 from 3.83% for the six months ended June 30, 2020, due primarily to a decrease in market interest rates, driven by decreases in the targeted federal funds rate in response to the COVID-19 pandemic. The average balance of interest-earning assets increased to $233.2 million for the six months ended June 30, 2021 from $202.7 million for the six months ended June 30, 2020, due primarily to increases in investment securities, partially offset by decreases in loans receivable and interest-bearing deposits with banks. Total interest expense decreased $175,000, or 34.2%, when comparing the two periods due to a decrease in the average cost of interest-bearing liabilities, partially offset by an increase in the average balance of interest-bearing liabilities. The average cost of interest-bearing liabilities decreased to 0.40% for the six months ended June 30, 2021 from 0.73% for the same period in 2020. The average balance of interest-bearing liabilities increased to $167.2 million for the six months ended June 30, 2021 from $140.5 million for the same period in 2020, due primarily to an increase in the number and balance of savings and interest-bearing demand deposit accounts, partially offset by a decrease in time deposits. As a result of the changes in interest-earning assets and interest-bearing liabilities, the interest rate spread decreased to 2.98% from 3.10% and the net interest margin decreased to 3.09% from 3.32% for the six-month periods ended June 30, 2021 and 2020, respectively.
Noninterest income increased $42,000, or 14.8%, for the quarter ended June 30, 2021 as compared to the same period in 2020, due primarily to increases of $75,000, $37,000, and $34,000 in brokered loan fees, deposit account service charges and ATM and debit card fee income, respectively, partially offset by a reduction of $104,000 in net gain on sales of securities available for sale. Proceeds from sales of securities available for sale were $4.5 million for the quarter ended June 30, 2020. No available for sale securities have been sold during the quarter ended June 30, 2021.
Noninterest income increased $144,000, or 31.6%, for the six months ended June 30, 2021 as compared to the same period in 2020, due primarily to increases of $136,000, $72,000, and $38,000 in brokered loan fees, ATM and debit card fee income and deposit account service charges, respectively, partially offset by a reduction of $104,000 in net gain on sales of securities available for sale. Proceeds from sales of securities available for sale were $4.5 million for the six months ended June 30, 2020. No available for sale securities have been sold during the six months ended June 30, 2021.
Noninterest expense increased $175,000, or 12.0%, for the quarter ended June 30, 2021 as compared to the same period in 2020. The increase was due primarily to increases in compensation and benefits of $110,000, data processing fees of $32,000, occupancy and equipment expenses of $25,000, deposit insurance premiums of $15,000 and other expenses of $27,000, partially offset by decreases in professional fees of $35,000.
Noninterest expense increased $401,000, or 14.3%, for the six months ended June 30, 2021 as compared to the same period in 2020. The increase was due primarily to increases in compensation and benefits of $245,000, occupancy and equipment expenses of $50,000, deposit insurance premiums of $30,000, directors’ compensation expense of $20,000, data processing fees of $17,000 and other expenses of $44,000 partially offset by decreases in professional fees of $17,000.
The Company recorded an income tax expense of $6,000 for the quarter ended June 30, 2021, compared to an expense of $33,000 for the same period in 2020. Income tax expense for the six months ended June 30, 2020 was $23,000 compared to $85,000 for the same period in 2020 resulting from a reduction in our effective tax rate to 2.9% for 2021 compared to 10.5% for 2020. The decrease in the effective tax rate is due largely to increased tax-exempt investment income proportionate to overall pre-tax income.
Balance Sheet Review
Total assets as of June 30, 2021 were $249.2 million compared to $235.4 million at December 31, 2020. Increases in cash and cash equivalents and investment securities of $8.9 million and $7.3 million, respectively were partially offset by a $2.4 million decrease in net loans. Investment securities increased due primarily to $13.0 million in purchases of available for sale investment securities, partially offset by $4.8 million in scheduled principal payments and maturities of mortgage-backed and tax-exempt securities. The decrease in net loans was due primarily to decreases of $2.1 million in commercial real estate loans and $2.4 million in one-to-four family residential loans, partially offset by increases in commercial business loans and commercial real estate construction loans of $2.3 million and $1.1 million, respectively. Total