Co-investment services revenue increased by £12.8 million, or 66%, for the nine months ended September 30, 2022 compared to the nine months ended September 30, 2021. The increase in co-investment services revenue was driven primarily through increased fees linked to capital raising. Fees from public markets activities increased to £21.2 million from £14.2 million during the nine months ended September 30, 2022 and September 30, 2021, respectively. The increase in public markets activity was driven by increase in management fees earned from increased market capitalization of LXi REIT PLC and Home REIT PLC. Revenues from private market activities increased to £11.1 million during the nine months ended September 30, 2022 from £5.3 million during the nine months ended September 30, 2021. This increase was driven primarily by £2.6 million exit fee earned from a certain real estate investment and increase in overall Co-investment business activity.
Merchant banking services revenue decreased by £1.6 million, or 25%, for the nine months ended September 30, 2022 compared to the nine months ended September 30, 2021. Merchant banking fees are generally success-based, and therefore financial performance reflects the prevailing market economic conditions which had deteriorated in the first nine months of 2022 relative to 2021.
Family office services revenue increased by £1.3 million, or 22%, for the nine months ended September 30, 2022 compared to the nine months ended September 30, 2021. The increase is in relation to new investment management fees for Alvarium Fund Managers (UK) Limited. Fees under family office services revenues are based on hourly staff charge out rates or fixed fee arrangements, and are not driven by changes in AUM.
Expenses
The Nine Months Ended September 30, 2022 Compared to the Nine Months Ended September 30, 2021
Cost of sales increased by £16.6 million, or 51%, for the nine months ended September 30, 2022 compared to the nine months ended September 30, 2021, primarily due to increased headcount and staff related costs, including an exceptional one-time LTIP payout of £10.4 million. Commissions paid under external revenue share agreements also increased by £3.0 million due an increase in amounts owed under revenue-sharing arrangements with third parties from real estate carried interest exits during the nine months ended September 30, 2022 compared to minimal activity during the nine months ended September 30, 2021.
Operating expenses, net of other operating income increased by £13.2 million, or 89%, for the nine months ended September 30, 2022 compared to the nine months ended September 30, 2021, due primarily to an increase of legal and other professional fees of £7.7 million, driven in part by the transactions contemplated by the Business Combination Agreement as well as other business activity, increases in corporate travel of £0.8 million, and irrecoverable VAT/Taxes of £0.4 million. Additionally, operating expenses increased by £1.6 million during the nine months ended September 30, 2022 due to amortisation of the intangible asset recognized upon acquisition of Prestbury Investment Partners Limited.
Other income, net increased by £2.5 million, or 92%, for the nine months ended September 30, 2022 compared to the nine months ended September 30, 2021, primarily due to a gain recognized on disposal of joint venture investment Alvarium NZ of £4.6 million, which was offset by an overall decrease in profits from joint ventures of £(1.5) million and a decrease in income from other fixed asset investments of £(0.5) million, during the nine months ended September 30, 2022.
Interest expense, net of interest income increased by £1.5 million, or 120%, for the nine months ended September 30, 2022 compared to the nine months ended September 30, 2021, primarily due to interest accrued on the loan used to finance the acquisition of Prestbury Investment Partners Limited.
Income tax benefit of £0.7 million was recognized for the nine months ended September 30, 2022 compared to income tax benefit of £0.6 million recognized during the nine months ended September 30, 2021. Income tax benefit was recognized primarily due to the full recognition of deferred tax assets in the UK by Alvarium Investments Limited in 2021. Specifically, the increased stake in LXi REIT Advisors Limited, as well as improved results of Alvarium Investment Advisors in the United States, allowed for full recognition and utilization of the deferred tax assets. The effective rate for the nine months ended September 30, 2022 has been increased by non-deductible expenses related to the transactions contemplated by the Business Combination Agreement, as referenced in the operating expense comments above.
Profit attributable to non-controlling interests decreased by £(0.75) million for the nine months ended September 30, 2022 compared to the nine months ended September 30, 2021, due to a reduction in non-controlling interests held outside the group in both LXi REIT Advisors Limited and Alvarium Social Housing Advisors Limited, which became wholly owned.
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