The decrease in total revenue resulted primarily from lower gold sales at Mount Milligan and Pueblo Viejo and lower gold production at Cortez and Peñasquito, and lower average gold, silver and copper prices. The decrease was partially offset by higher silver sales at Khoemacau, which shipped its first concentrate during the prior year quarter.
Cost of sales, which excludes depreciation, depletion and amortization, decreased to $23.2 million for the third quarter, from $27.2 million for the three months ended September 30, 2021. The decrease, when compared to the prior period, was primarily due to a decrease in gold and silver sales at Pueblo Viejo and lower gold sales at Mount Milligan, offset by higher silver sales at Khoemacau. Stream deliveries from Khoemacau began in the prior year comparable quarter. Cost of sales is specific to our stream agreements and is the result of our purchase of gold, silver and copper for a cash payment. The cash payment for gold from Mount Milligan is the lesser of $435 per ounce or the prevailing market price of gold when purchased, while the cash payment for our other streams is a set contractual percentage of the gold, silver or copper (Mount Milligan) spot price near the date of metal delivery.
General and administrative costs increased to $7.6 million for the third quarter, from $7.1 million for the three months ended September 30, 2021. The increase was primarily due to an increase in employee-related costs including non-cash compensation expense.
Depreciation, depletion and amortization decreased to $37.8 million for the third quarter, from $50.6 million for the three months ended September 30, 2021. The decrease was primarily due to lower gold production at Cortez and lower gold sales at Mount Milligan as well as lower depletion rates at Mount Milligan compared to the prior period. The gold and copper depletion rates on the Mount Milligan stream as of September 30, 2022 decreased to $416 per ounce of gold and $1.06 per pound of copper as a result of the increase to proven and probable reserves in the updated Mount Milligan life of mine plan. The decrease was partially offset by additional depletion from Khoemacau which produced first deliveries in the prior year comparable quarter.
Interest and other expense increased to $8.8 million for the third quarter, from $1.9 million for the three months ended September 30, 2021. The increase was primarily due to higher interest expense as a result of the $500 million draw on the revolving credit facility and foreign exchange losses related to the GBR acquisition.
For the third quarter the Company recorded an income tax expense of $11.0 million, compared with income tax expense of $16.0 million for the three months ended September 30, 2021. The income tax expense resulted in an effective tax rate of 19.3% in the current period, compared with 18.5% for the three months ended September 30, 2021.
Net cash provided by operating activities totaled $95.0 million for the third quarter, compared to $129.9 million for the prior year period. The decrease was primarily due to a decrease in cash proceeds received from the Company’s stream and royalty interests in the third quarter.
Net cash used in investing activities totaled $678.6 million for the third quarter, compared to $272.7 million for the prior year period. The increase was primarily due to higher acquisitions of stream and royalty interests compared to the prior year period.
Net cash provided by financing activities totaled $425.3 million for the third quarter, compared to net cash used in financing activities of $163.0 million for the prior year period. The change was primarily due to a net draw of $450 million on the Company’s revolving credit facility in the third quarter compared to a net repayment of $100.0 million during the prior year period.
At September 30, 2022, the Company had current assets of $181.8 million compared to current liabilities of $64.5 million, which resulted in working capital of $117.3 million and a current ratio of approximately 3 to 1. This compares to current assets of $216.0 million and current liabilities of $61.4 million at December 31, 2021, resulting in working capital of $154.6 million and a current ratio of approximately 4 to 1. The decrease in working capital was primarily due to a decrease in available cash as a result of the Cortez Complex Royalty and GBR acquisitions.
During the third quarter, liquidity needs were met from $95.0 million in net cash provided by operating activities and available cash resources.
Other Corporate Updates
Repayment of $50 Million of Revolving Credit Facility Balance Leaving $550 Million Available
As previously announced, on July 25, 2022, the Company drew $500 million on its revolving credit facility to fund the acquisition of the Cortez Complex Royalty. In keeping with Royal Gold’s capital allocation strategy to repay outstanding debt as cash flow allows, the Company repaid $50 million of the credit facility balance on September 6, 2022, leaving an outstanding balance of $450 million and $550 million available under the credit facility at quarter end.
Outlook