Increased -- thank you, Bob -- from 12% in Q2 to 13% in Q3. Selling expense was $1.4 million for the third quarter, compared to $1.5 million in the second quarter, a decrease of $77,000, or 5%. The decrease was driven by reductions in spending on advertising and sales related travel.
Engineering and product development expense was $905,000 for the third quarter, compared to $982,000 for the second quarter, a decrease of $77,000, or 8% sequentially. The decrease was related to reduced product development costs in our Thermal Products segment.
General and administrative expense was $1.6 million for the third quarter compared with $2.1 million in the second quarter, a decrease of $571,000, or 27%. Our second quarter G&A expense included $456,000, or $0.04 per diluted share in acquisition related expenses compared to $23,000 of acquisition-related expenses in the third quarter. When adjusted to remove these items, third quarter G&A expense decreased $138,000, or 8% sequentially. The decrease was primarily the result of lower levels of stock-based compensation expense related to restricted stock awards granted to our three independent directors, which fully vested upon the re-election to our board at the end of the second quarter. In addition, there were lower levels of profit related bonuses and reduced professional fees in the third quarter as compared to the second.
Other income as $17,000 for the third quarter compared to $18,000 for the second quarter and we accrued income tax expense of $631,000 in the third quarter, compared to $263,000 accrued in the second quarter. Our effective tax rate increased to 37% in the third from 35% in the second quarter, and the increase in our effective tax rate was the result of the repatriation of $1.0 million from our German operation during the quarter, and the incremental U.S. income tax that needed to be accrued on that dividend.
At September 30, 2016, our deferred tax assets were $1.1 million and our remaining net loss carried forward was $1.0 million for domestic state (primarily California) and $70,000 for foreign related to our German operation. We expect that our tax rate for the fourth quarter of 2016 will be in the range of 34% to 36%.
Third quarter net income was $1.1 million, or $0.11 per diluted share, compared with second quarter net income of $486,000, or $0.05 per diluted share. Diluted average shares outstanding were 10,319,000 at September 30. We resumed our stock buyback in early September and during the third quarter, we repurchased 18,546 shares at a net cost of $72,000, or $3.85 per share. As of September 30, 2016 we had repurchased a cumulative total of 250,603 shares, or just under 2.5%, of our outstanding common stocks at a net cost of $997,000, or $3.95 per share. We had suspended our stock buyback in May 2016 as we commenced significant due diligence for an acquisition opportunity that had been expected to close on August 1, 2016.
Amortization and depreciation expense was $148,000 for the third quarter, and EBITDA was $1.9 million for the third quarter, up from $882,000 in EBITDA for the second quarter. Consolidated headcount at the end of September (which includes temporary staff) was 118, an increase of 1 from the staff level we had at June 30.
I'll now turn to our balance sheet. Cash and cash equivalents at the end of the second quarter were $26.3 million, up $1.3 million from June 30. We currently expect cash and cash equivalents to increase in the fourth quarter of 2016.
Accounts receivable was essentially unchanged sequentially at $6.7 million.
Inventory increased slightly by $83,000 to $3.4 million at September 30.
Capital expenditures during the third quarter were $118,000, down slightly from $126,000 in the second quarter, and represented new computer hardware related to a company-wide system upgrade and additions to our leased product inventory in our German operation.
Bob provided consolidated and segment revenue on booking data earlier in the call. The backlog at the end of September was $6.1 million, up from $5.7 million at the end of June.
In terms of our financial outlook, as noted in our earnings release, we expect that net revenues for the quarter ended December 31, 2016 will be in the range of $9 million to $10 million and that net earnings will range from $0.02 to $0.06 per diluted share. We currently expect that our Q4 2016 product mix will be consistent with Q3 and that the fourth quarter gross margin will range from 46% to 49%.
Operator, that concludes our formal remarks. We can now take questions.