price per pound by approximately $2.54, partially offset by higher raw material market prices, which increased product average selling price per pound by approximately $0.96.
Sales to the aerospace market were $89.1 million in the first nine months of fiscal 2021, a decrease of 43.7% from $158.4 million in the same period of fiscal 2020, due to a 43.6%, or 2.7 million pound, decrease in volume. The decrease in volume was due to the impact of COVID-19 on the aerospace market and the reduced demand in the supply chain for the Boeing 737 MAX. The lower average selling price per pound shipped reflects a lower-value product mix, increased competition and other pricing factors, which decreased average selling price per pound by $0.98, partially offset by higher raw material market prices, which increased average selling price per pound by approximately $0.90.
Sales to the chemical processing market were $47.3 million in the first nine months of fiscal 2021, an increase of 5.9% from $44.7 million in the same period of fiscal 2020, due to a 3.8% increase in average selling price per pound coupled with a 2.0% increase in volume. The average selling price per pound reflects an increase in raw material market prices and a higher-value product mix, which increased average selling price per pound by approximately $1.81, partially offset by increased competition and other pricing factors, which decreased average selling price per pound by approximately $0.99.
Sales to the industrial gas turbine market were $48.2 million in the first nine months of fiscal 2021, an increase of 9.3% from $44.1 million for the same period of fiscal 2020, due to an increase in volume of 16.5%, partially offset by a decrease in average selling price per pound of 6.2%, or $1.06. The increase in volume is primarily attributable to the impact of the Company’s share gain initiative. The decrease in average selling price per pound primarily reflects lower pricing due to competition and other factors combined with a lower- value product mix, which decreased average selling price per pound by approximately $2.05, partially offset by higher raw material market prices, which increased the average selling price per pound by approximately $0.99.
Sales to other markets were $42.0 million in the first nine months of fiscal 2021, an increase of 17.3% from $35.8 million in the same period of fiscal 2020, due to a 51.2% increase in volume, partially offset by a 22.4% decrease in average selling price per pound. The increase in volume was primarily due to an increase in sales to the flue-gas desulfurization market. The decrease in average selling price reflects a lower-value product mix, increased competition and other factors, which decreased average selling price per pound by approximately $8.97, partially offset by higher raw material market prices, which increased average selling price per pound by approximately $0.88.
Other Revenue. Other revenue was $15.7 million in the first nine months of fiscal 2021, a decrease of 10.6% from $17.5 million in the same period of fiscal 2020. The decrease was primarily due to decreased toll conversion.
Cost of Sales. Cost of sales was $219.4 million, or 90.5% of net revenues, in the first nine months of fiscal 2021 compared to $259.9 million, or 86.5% of net revenues, in the same period of fiscal 2020. This decrease was primarily due to lower volumes sold combined with continued traction in the Company’s cost reduction initiatives, partially offset by lower fixed-cost absorption.
Gross Profit. As a result of the above factors, gross profit was $23.0 million for the first nine months of fiscal 2021, a decrease of $17.6 million from the same period of fiscal 2020. Gross profit as a percentage of net revenue decreased to 9.5% in the first nine months of fiscal 2021 as compared to 13.5% in the same period of fiscal 2020.
Selling, General and Administrative Expense. Selling, general and administrative expense was $32.5 million for the first nine months of fiscal 2021, an increase of $0.3 million from the same period of fiscal 2020. This increase is primarily attributable to higher incentive compensation expenses, which were partially offset by significant cost-saving measures taken as a result of the COVID-19 pandemic, including headcount reductions and other measures. Selling, general and administrative expense as a percentage of net revenues increased to 13.4% for the first nine months of fiscal 2021 compared to 10.7% for the same period of fiscal 2020.
Research and Technical Expense. Research and technical expense was $2.5 million, or 1.0% of net revenue, for the first nine months of fiscal 2021, compared to $2.8 million, or 0.9% of net revenue, in the same period of fiscal 2020. The decrease was primarily due to lower salary expenses.
Operating Income/(Loss). As a result of the above factors, operating loss in the first nine months of fiscal 2021 was $(11.9) million compared to an operating income of $5.8 million in the same period of fiscal 2020.
Nonoperating retirement benefit expense. Nonoperating retirement benefit expense was $1.1 million in the first nine months of fiscal 2021 compared to $5.1 million in the same period of fiscal 2020. The decrease in expense was primarily driven by favorable retiree health care spending and higher than expected return on plan assets in the September 30, 2020 valuation.