Net sales for the three months ended September 30, 2019 increased by US$ 128.9 million or 50.5% to US$ 383.8 million compared to US$ 255.0 million in the same period in 2018. Net sales of wind blades increased by 49.9% to US$ 352.2 million for the three months ended September 30, 2019 as compared to US$ 234.9 million in the same period in 2018.
The increase was primarily driven by a 44% increase in the number of wind blades produced year over year largely as a result of increased production at their China, Mexico and Turkey facilities. Total billings for the three months ended September 30, 2019 increased by US$ 144.9 million or 60.2% to US$ 385.6 million compared to US$ 240.7 million in the 2018 period.
Total cost of goods sold for the three months ended September 30, 2019 was US$ 357.9 million and included US$ 13.1 million related to ten lines in startup in their plants in China and Mexico and the startup of new wind blade models for a customer in Turkey and US$ 9.0 million of transition costs related to eight lines in transition during the quarter. eneral and administrative expenses for the three months ended September 30, 2019 totaled US$ 10.6 million, or 2.8% of net sales.
Income taxes reflected a provision of US$ 18.8 million for the quarter as compared to a benefit of US$ 10.3 million for the same period in 2018.
The net loss for the three months ended September 30, 2019 was US$ 4.6 million as compared to net income of US$ 9.5 million in the same period in 2018.
The net loss for the three months ended September 30, 2019 was US$ 4.6 million as compared to net income of US$ 9.5 million in the same period in 2018.
EBITDA for the quarter increased to US$ 26.3 million, compared to US$ 7.4 million during the same period in 2018. Adjusted EBITDA for the quarter increased to US$ 27.6 million compared to US$ 17.6 million during the same period in 2018. Adjusted EBITDA margin increased slightly to 7.2% compared to 6.9% during the same period in 2018.