This includes the Bank and the Comerica Charitable Foundation, together providing $11 million in assistance to local communities and businesses.
We funded $3.9 billion in PPP loans to small and medium-sized companies.
, Civic 50, CDP and Corporate Nights.
And our net charge-offs for the year were 38 basis points or 14 basis points excluding energy.
We maintained our strong capital levels and booked -- our book value grew 7% to over $55 per share.
We generated earnings of $215 million or $1.49 per share, a 3% increase over the third quarter, driven by an increase in revenue and strong credit quality.
While lower on a quarter-over-quarter basis, average loans increased in December relative to November by nearly $300 million excluding PPP loan repayments.
Average deposits increased by nearly $1.5 billion to an all-time high with 55% of the growth derived from non-interest-bearing accounts.
Net interest income increased $11 million benefiting from our continued careful management of loan-to-deposit pricing, combined with the contribution from fees related to PPP loan forgiveness.
As far as credit, our metrics remained strong and our provision was a credit of $17 million.
Criticized loans declined and net charge-offs were only 22 basis points.
Positive portfolio migration and the slight improvement in the economic forecast resulted in a reduction of the credit reserve to just under $1 billion or nearly three times non-performing assets.
Non-interest income increased $30 million or 5% as customer activity continued to rebound.
Our capital levels remained strong.
Our CET1 ratio increased to 10.35%, above our target of 10%.
Average loans decreased approximately $600 million or 1%, which compared favorably to the industry HA data.
Technology and Life Sciences loans declined about $180 million, mainly due to M&A and increased liquidity, driven by fundraising activity and companies reducing cash burn.
Equity Funds Services, which provides capital call lines to investment companies increased $244 million as activity has picked up with new fund formation.
National Dealer increased $190 million as inventory levels are rebuilding, yet remains $2 billion below fourth quarter 2019.
Period end loans were stable and included a decline in PPP balances of $298 million, primarily due to loan forgiveness.
Line utilization at year end for the total portfolio remained relatively low at 48%.
Average deposits increased 2% or $1.5 billion to a new record of $70.2 billion, as shown on Slide 7.
Period end deposits increased over $4.4 billion.
Timing of monthly benefit activity in our government prepaid card business increased balances by $2.2 billion at quarter end.
With strong deposit growth, our loan-to-deposit ratio decreased to 72%.
The average cost from interest-bearing deposits reached an all-time low of 11 basis points, a decrease of six basis points from the third quarter and our total funding cost fell to only 10 basis points.
This was due to the third quarter purchase of $2.25 billion in additional securities, primarily treasuries, as we took some action to put some of our excess liquidity to work.
The additional securities combined with lower rates on the replacement of prepays, which totaled about $1 billion, resulted in the yield on the portfolio declining to 1.95%.
We expect repayments of MBS to continue to be about $1 billion per quarter and yields on reinvestments to be in the low-to-mid 100 basis point range.
Net interest income increased $11 million to $469 million and the net interest margin was up three basis points to 2.36%.
Interest income on loans increased $6 million, adding four basis points to the margin.
Higher fees, mostly related to PPP loan forgiveness and continued pricing actions as loans renew, together added $10 million and four basis points to the margin.
Other portfolio dynamics, including higher non-accrual income, added $1 million.
The decrease in loans had a $5 million unfavorable impact.
Lower securities yields had a $6 million or three basis point negative impact.
This was mostly offset by the higher balance, which added $5 million.
Average balances of the Fed increased over $500 million, impacting the margin by one basis point.
Our extraordinarily high Fed balances of $13 billion continue to weigh heavily on the margin with the gross impact of approximately 43 basis points.
Finally, prudent management of deposit pricing added $5 million and three basis points to the margin and lower rates on wholesale funding added $1 million.
Gross charge-offs were only $39 million, a decrease of $14 million from the third quarter.
Net charge-offs were $29 million or 22 basis points.
Non-performing assets increased $24 million, yet remained below our historical norm at 69 basis points of total loans.
Criticized loans declined $459 million and comprised 6% of the total portfolio.
As the path to full economic recovery remains uncertain due to the unprecedented challenges of the COVID-19 pandemic, our reserve ratio remains elevated at 1.90% or 2.03%, excluding PPP loans.
Criticized loans were stable and non-accruals remain under 1%.
This segment has performed better than expected, but issues can be lumpy and sudden and resulted in net charge-offs of $21 million in the fourth quarter.
Energy loans decreased 13% to $1.6 billion at quarter end, representing 3% of our total loans.
Non-interest income increased $13 million, as outlined on Slide 12, continuing the positive trend we've seen since post the shutdown of the economy earlier last year.
Customer derivative income increased $8 million with higher volume due to interest rate swaps and energy hedges, combined with the change in the impact from the credit valuation adjustment.
Specifically, there was an unfavorable adjustment of $6 million in the third quarter and a favorable adjustment of less than $1 million in the fourth quarter.
Commercial lending fees increased $5 million with the seasonal pickup in syndication activity and higher unutilized line fees.
Securities trading income, which includes fair market adjustments for investments we hold related to our Technology and Life Sciences business, decreased $5 million from elevated levels generated over the last couple of quarters.
Note, deferred comp asset returns were $9 million, a $1 million increase from the third quarter and are offsetting non-interest expenses.
Salaries and benefits increased $14 million with higher performance-based incentives, severance, staff insurance expense and technology-related labor.
We realized a $7 million increase in outside processing due to card activity, technology spend as well as PPP program costs.
Occupancy increased $2 million due to a catch-up in maintenance projects that were delayed due to COVID as well as seasonal expenses.
Our CET1 ratio increased to an estimated 10.35%, above our target of 10%.
However, this will be more than offset by Mortgage Banker declining from its record high due to seasonally lower purchase and refi volumes.
We are currently in the process of deploying some excess liquidity by repaying $2.8 billion of FHLB advances over an eight week period, which will provide a modest lift.
However, with our credit reserve at year end at over 2% of loans, excluding PPP, we believe we are well positioned to manage through this period of economic uncertainty.
Our pension expense is expected to decline $9 million in the first quarter to get to the new run rate for 2021.
As I mentioned, we do not forecast deferred comp of $9 million to repeat.
We expect a 22% tax rate, excluding discrete items.
This has been demonstrated by our ROE, which increased over 11% in the fourth quarter and our book value per share, which grew 7% over the past year as well as the current dividend yield, which remains above 4%.

Summary:
We generated earnings of $215 million or $1.49 per share, a 3% increase over the third quarter, driven by an increase in revenue and strong credit quality.
Criticized loans declined and net charge-offs were only 22 basis points.
Our capital levels remained strong.
Net interest income increased $11 million to $469 million and the net interest margin was up three basis points to 2.36%.
However, this will be more than offset by Mortgage Banker declining from its record high due to seasonally lower purchase and refi volumes.