Gas & Petroleum Transmission gross profit totaled $1.2 million for the three months ended June 30, 2022, a $882,000 increase from $276,000 for the three months ended June 30, 2021. Gas & Petroleum Transmission gross profit totaled $3.6 million for the nine months ended June 30, 2022, a $428,000 increase from $3.2 million for the nine months ended June 30, 2021. The gross profit increases were primarily related to transmission work that was awarded due to increased construction opportunities from the Company’s existing transmission clients.
Electrical, Mechanical, & General services and construction gross profit totaled $1.6 million for the three months ended June 30, 2022, a $638,000 increase from $1.0 million for the three months ended June 30, 2021. Electrical, Mechanical, & General services and construction gross profit totaled $3.9 million for the nine months ended June 30, 2022, a $844,000 increase from $3.0 million for the nine months ended June 30, 2021. The increases were primarily related to an increase in gross profit generated by general and civil construction services, partially offset by gross losses generated by start-up mechanical and electrical divisions.
Unallocated shop gross profit totaled $852,000 for the three months ended June 30, 2022, a $1.8 million increase from ($1.0 million) for the three months ended June 30, 2021. Unallocated shop gross profit totaled $255,000 for the nine months ended June 30, 2022, a $3.9 million increase from ($3.7 million) for the nine months ended June 30, 2021. The increase in unallocated shop gross profit was due to increased internal equipment charges to projects for the three and nine months ended June 30, 2022, as compared to the same periods in the prior year and a focused effort to manage project and shop costs.
Selling and administrative expenses. Total selling and administrative expenses increased by $613,000 to $3.8 million for the three months ended June 30, 2022, as compared to $3.2 million for the same period in the prior year. Total selling and administrative expenses increased by $243,000 to $10.9 million for the nine months ended June 30, 2022, as compared to $10.6 million for the same period in the prior year.
Selling and administrative expenses increased by $200,000 for the three months ended June 30, 2022, as compared to the same period in the prior year for new business operations acquired in fiscal year 2022. Also, selling and administrative expenses for companies started in fiscal year 2021 grew by $250,000 for the three months ended June 30, 2022, as compared to the same period in the prior year.
Selling and administrative expenses increased by $1.5 million for the nine months ended June 30, 2022, as compared to the same period in the prior year for growth related to new business, partially offset by a $990,000 reduction in incentive compensation and increased labor charges to projects.
Interest income. Interest income totaled $0 and $600, respectively, for the three and nine months ended June 30, 2022, as compared to $0 and $152,000 for the same periods in the prior year. The decrease in interest income was primarily due to the timing of recognizing interest earned from the Company’s captive insurance surety deposit.
Paycheck Protection Program loan forgiveness. The Company recorded $9.8 million in non-taxable income related to PPP loan forgiveness during the three and nine months ended June 30, 2021, to extinguish all PPP loan debt.
Other nonoperating (expense) income. Other nonoperating expense totaled $175,000 for the three months ended June 30, 2022, an increase of $139,000 from $36,000 for the same period in the prior year. Other nonoperating expense totaled $438,000 for the nine months ended June 30, 2022, an increase of $317,000 from $121,000 for the same period in the prior year. The increases were primarily related to an increase in intangible asset amortization expense.
Interest expense. Interest expense totaled $206,000 for the three months ended June 30, 2022, an increase of $69,000 from $137,000 for the same period in the prior year. Interest expense totaled $549,000 for the nine months ended June 30, 2022, an increase of $192,000 from $357,000 for the same period in the prior year. The increase in interest expense was primarily due to the financing of the recent acquisitions.
Gain on sale of equipment. Gain on sale of equipment totaled $58,000 for the three months ended June 30, 2022, a decrease of $77,000 from $135,000 for the same period in the prior year. Gain on sale of equipment totaled $418,000 for the nine months ended June 30, 2022, a decrease of $210,000 from $628,000 for the same period in the prior year. The decrease was related to a decrease in equipment sold.