Loans
Loans decreased $201 million, or 3.3%, compared to the prior quarter, to $5.8 billion as of September 30, 2021, and increased $683 million, or 13.3%, compared to September 30, 2020. New loan fundings in the third quarter of 2021 were $802 million, a decrease of $331 million, or 29.0%, from the second quarter of 2021 and an increase of $389 million, or 94.1%, from the third quarter of 2020. The reduction in loan fundings quarter over quarter was primarily due to a typical seasonal slowdown during the summer months as well as some fundings in our multifamily business that were extended until the fourth quarter. Excluding our securitization during the quarter, loans would have increased $219 million, or 3.6%, compared to the prior quarter to $6.2 billion. Contributing to loan originations during the quarter, our C&I division funded $346 million of new commercial loans during the third quarter of 2021, of which 52% were adjustable commercial revolving lines of credit. The remaining C&I originations were comprised of $77 million of commercial term loans, $40 million of public finance loans, $28 million of owner occupied commercial real estate loans, and $21 million of equipment finance leases. We funded no additional PPP loans during the quarter. Loan balances during the third quarter of 2021 were also impacted by loan payoffs of $583 million, compared to payoffs of $613 million in the second quarter of 2021 and $383 million in the third quarter of 2020. The current pipeline remains very strong going into the fourth quarter.
Investment Securities
Investment securities increased $155.9 million, or 20.9%, from the prior quarter, to $901.7 million as of September 30, 2021, and increased $18.8 million, or 2.1%, compared to September 30, 2020. The increases in the balance of investment securities compared to the second quarter of 2021 and third quarter of 2020 were primarily driven by securities purchases in the third quarter of 2021.
The allowance for credit losses for investments increased by $1.0 million from the prior quarter, to $10.1 million as of September 30, 2021. The increase was a result of the lower interest rate environment and faster than expected prepayments that negatively impacted the projected cash flows on FFB’s interest-only strip securities.
Deposits and Borrowings
Deposits were $6.8 billion as of September 30, 2021, a decrease of $262 million, or 3.7%, compared to the prior quarter, and an increase of $1.4 billion, or 25.3%, compared to the third quarter of 2020. Deposit growth during the third quarter of 2021 compared to the third quarter of 2020 was primarily driven by an increase of $1.1 billion, or 58%, in non-interest bearing demand deposits, an increase of $548.7 million, or 138%, in interest bearing demand deposits, and an increase in money market and savings accounts of $368 million, largely attributable to our commercial deposit services division, and retail branches. The increases in deposits were offset by a reduction in CDs of $641 million, primarily due to our intentional run-off of higher cost brokered deposits. Noninterest-bearing demand deposits measured 43.8% of total deposits as of September 30, 2021, compared to 46.1% of total deposits as of June 30, 2021, while core deposits decreased by $248 million compared to the linked quarter, and measured 98% of total deposits as of September 30, 2021 and June 30, 2021. Commercial business deposits were 74% of total core deposits as of September 30, 2021.
Our loan to deposit ratio measured 84.9% as of September 30, 2021, compared to 84.6% as of June 30, 2021 and 93.9% as of September 30, 2020.