Management Fees. Management fees increased by $57.9 million, or 157%, for the three months ended March 31, 2021 compared to the three months ended March 31, 2020. The increase was primarily due to the expiration of the ORCC fee waiver, which expired on October 18, 2020. Fee waivers were $43.0 million for the three months ended March 31, 2020. The remaining increase is due to the 35% increase in average FPAUM as of March 31, 2021 compared to March 31, 2020.
Administrative, Transaction and Other Fees. Administrative, transaction and other fees increased by $1.1 million, or 9%, for the three months ended March 31, 2021 compared to the three months ended March 31, 2020. Administrative, transaction and other fees primarily include fee income, administrative fees and dealer manager revenue. The increase was driven by an increase in administrative fees and fee income, partially offset by a decrease in dealer manager revenue. Fee income, which is income earned from portfolio companies for providing arrangement, syndication, origination, structuring analysis, capital structure and business plan advice and other services, increased from $7.6 million to $9.0 million for the three months ended March 31, 2021 as compared to the three months ended March 31, 2020. The increase was primarily due to higher fee income from portfolio companies for the three months ended March 31, 2021, a result of higher demand for such services as well as an increase in origination activity. Administrative fees increased from $2.8 million to $3.5 million for the three months ended March 31, 2021 as compared to the three months ended March 31, 2020. Administrative fees were higher for the three months ended March 31, 2021 due to the overall growth of the business and staff required to support the business. Dealer manager revenue was lower for the three months ended March 31, 2021 due to slower broker dealer fundraising.
Expenses
The Three Months Ended March 31, 2021 Compared to the Three Months Ended March 31, 2020
Compensation and Benefits. Compensation and benefits increased by $15.8 million, or 49%, for the three months ended March 31, 2021 compared to the three months ended March 31, 2020. The increases were primarily driven by headcount growth of 30% from March 31, 2020 to March 31, 2021, merit increases and long-term compensation award increases for the comparative periods.
General, Administrative and Other Expenses. General, administrative and other expenses decreased by $4.4 million, or 23%, for the three months ended March 31, 2021 compared to the three months ended March 31, 2020. The decrease was primarily driven by a $4.3 million decrease in expense support related to ORCC II. Additionally, certain expenses have increased during this period, including occupancy costs, and technology to support our growing headcount and expansion of our business. The three months ended March 31, 2021 was also impacted by the COVID-19 pandemic and resulted in a decrease in certain operating expenses.
Interest Expense. Interest expense remains relatively consistent for the three months ended March 31, 2021 and 2020.
Income Tax Expense (Benefit). Income tax expense increased by $0.2 million for the three months ended March 31, 2021 compared to the three months ended March 31, 2020. Income taxes are a result of Owl Rock’s taxable income (loss), which for the three months ended March 31, 2021 was positive as compared to a net loss for the three months ended March 31, 2020.
Non-Controlling Interests. Net income (loss) attributable to non-controlling interests in Owl Rock entities represents results attributable to third parties in our operating subsidiaries. Net income (loss) is generally allocated based on such ownership interests held by third parties with respect to each of these entities.
Net income (loss) attributable to non-controlling interests in Owl Rock entities decreased by $0.8 million for the three months ended March 31, 2021 compared to the three months ended March 31, 2020. The changes in the comparative periods are a result of the respective changes in income (loss) before taxes and changes in third party ownership interests in such Owl Rock entities.
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