the third quarter of 2021 as the weather improved and COVID-19 restrictions continued to lessen and allow for more in person gatherings.
Nine Months Ended September 30, 2021 Compared to the Same Period in 2020
Total non-interest expense for the nine months ended September 30, 2021 was $80.0 million, up $18.8 million or 30.8%, from the nine months ended September 30, 2020. The increase is largely attributable to the variable expenses from loan originations overall, particularly mortgage commissions. Total salaries and employee benefits expense was $61.8 million, an increase of $15.3 million or 32.9%, compared to the nine months ended September 30, 2020. Of this increase, $10.9 million relates to the mortgage segment as the number of employees in this segment have increased period over period. Salaries and benefits for the Bank and Wealth segments increased due to an increased level of full-time equivalent employees as well as increase in incentives and stock-based compensation expense.
Occupancy and equipment expense increased $301 thousand, or 9.5%, over the period due largely to the expansion of our physical office footprint into Maryland with 8 mortgage loan production offices having opened since early 2020. Professional fees were up $511 thousand, or 24.1%, over the period due largely to one-time consent fees incurred in 2021 related to the filing of the Corporation’s December 31, 2020 Form 10K, in conjunction with the change in Accountants we made in 2020. This is combined with an increase in consulting fees as Meridian continues to invest in various company-wide technology focused projects as discussed above. Advertising and promotion expenses were up $799 thousand, or 40.1%, over the same period due to the improvements to the economy and a pull back on COVID-19 related restrictions that has allowed bank employees to spend more time in business development and community outreach capacity.
INCOME TAXES
Income tax expense for the three months ended September 30, 2021 was $2.9 million, as compared to $2.8 million for the same period in 2020. The increase in income tax expense was attributable to the increase in earnings, period over period. Our effective tax rate was 23.3% for the third quarter of 2021 and 23.1% for the third quarter of 2020.
Income tax expense for the nine months ended September 30, 2021 was $8.5 million, as compared to $5.2 million, for the same periods in 2020. The increase in income tax expense was attributable to the increase in earnings, period over period. Our effective tax rate was 23.5% for the first nine months of 2021 and 23.0% for the first nine months of 2020.
BALANCE SHEET ANALYSIS
As of September 30, 2021, total assets were $1.8 billion, an increase of $42.2 million from December 31, 2020. Total assets increased $3.8 million, or 0.2%, from September 30, 2020 due to a higher level of cash, investments, commercial loans and PPP loans on the balance sheet as of September 30, 2020. Cash and cash equivalents increased $26.4 million due to liquidity from mortgage loans held for sale and PPP loan forgiveness. The securities available-for-sale portfolio grew to $146.1 million as of September 30, 2021, up $22.6 million, or 18.3%, from December 31, 2020. State and municipal securities increased $7.0 million and U.S. treasuries were up $15 million.
Total loans, net of allowance, grew $92.7 million, or 7.3%, to $1.4 billion as of September 30, 2021, from $1.3 billion as of December 31, 2020. There was growth in several commercial loan categories from December 31, 2020, as we continue to expand our presence in the Philadelphia market region. Small business loans increased $41.2 million, or 82.7%, commercial real estate loans increased $60.7 million, or 12.1%, and lease financings increased $45.2 million, or 136.8%, as our Meridian Equipment Finance (“MEF”) leasing team continued their strong growth pattern after starting up in early 2020. Residential real estate loans held for sale decreased $111.2 million, or 48.5%, to $118.0 million as of September 30, 2021, while PPP loans decreased $83.0 million, or 41.8%, over this period.
Servicing assets were $11.9 million as of September 30, 2021, up $6.3 million, or 112.4%, from December 31, 2020. $10.1 million of this balance is comprised of mortgage servicing rights, while $1.8 million is comprised of SBA loan servicing assets. The increase in both servicing asset types was the result of the continued strong loan sales markets since December 31, 2020.