Operating income* for the Other segment was $1.0 million for the three-months ended September 30, 2019, a decrease of approximately $0.7 million, or 42.3% lower than operating income of $1.7 million for the three-months ended September 30, 2018.
*Exclusive of corporate and unallocated expenses.
Interest and Other Income, net. Interest and other non-operating income, net, was $3.1 million for the three-months ended September 30, 2019, as compared to interest and other non-operating income, net, of $3.0 million for the three-months ended September 30, 2018. Foreign currency transaction losses were $2.8 million and $0.3 million for the three-months ended September 30, 2019 and 2018, respectively. Interest income was $6.1 million and $3.4 million for the three-months ended September 30, 2019 and 2018, respectively.
Provision for Income Taxes. Provision for income taxes was $99.6 million for the three-months ended September 30, 2019, an increase of $24.8 million, or 33.2% higher than the provision for income taxes of $74.8 million for the three-months ended September 30, 2018. The effective combined federal, state and foreign tax rate increased to 25.0% from 21.8% for the three-months ended September 30, 2019 and 2018, respectively. The increase in the effective tax rate was primarily attributable to increased income taxes in certain foreign jurisdictions as well as a decrease in the equity compensation deduction. In addition, the comparative effective tax rate for the three-months ended September 30, 2018 included a non-recurring tax benefit.
Net Income. Net income was $298.9 million for the three-months ended September 30, 2019, an increase of $31.2 million, or 11.7% higher than net income of $267.7 million for the three-months ended September 30, 2018. The increase in net income was primarily due to the $65.3 million increase in gross profit. The increase in net income was partially offset by an increase in the provision for income taxes of $24.8 million and an increase in operating expenses of $9.5 million.
Results of Operations for the Nine-Months Ended September 30, 2019 Compared to the Nine-Months Ended September 30, 2018.
Net Sales. Net sales were $3.18 billion for the nine-months ended September 30, 2019, an increase of approximately $300.7 million, or 10.4% higher than net sales of $2.88 billion for the nine-months ended September 30, 2018. Net sales for the nine-months ended September 30, 2019 were positively impacted by approximately $89.2 million as a result of the U.S. Price Increase and the Canada Price Increase, on certain of our Monster Energy® brand energy drinks. Net changes in foreign currency exchange rates had an unfavorable impact on net sales of approximately $60.1 million for the nine-months ended September 30, 2019.
Net sales for the Monster Energy® Drinks segment were $2.95 billion for the nine-months ended September 30, 2019, an increase of approximately $305.8 million, or 11.6% higher than net sales of $2.65 billion for the nine-months ended September 30, 2018. Net sales for the Monster Energy® Drinks segment increased primarily due to (i) sales of our Reign Total Body FuelTM high performance energy drinks, introduced in the first quarter of 2019, (ii) the price increases described above, and (iii) increased worldwide sales by volume of our Monster Energy® brand energy drinks as a result of increased consumer demand. Net changes in foreign currency exchange rates had an unfavorable impact on net sales for the Monster Energy® Drinks segment of approximately $51.1 million for the nine-months ended September 30, 2019.
Net sales for the Strategic Brands segment were $215.8 million for the nine-months ended September 30, 2019, a decrease of approximately $4.2 million, or 1.9% lower than net sales of $220.0 million for the nine-months ended September 30, 2018. Net changes in foreign currency exchange rates had an unfavorable impact on net sales for the Strategic Brands segment of approximately $9.0 million for the nine-months ended September 30, 2019.
Net sales for the Other segment were $17.0 million for the nine-months ended September 30, 2019, a decrease of approximately $0.9 million, or 4.9% lower than net sales of $17.9 million for the nine-months ended September 30, 2018.
Case sales, in 192-ounce case equivalents, were 342.7 million cases for the nine-months ended September 30, 2019, an increase of approximately 29.3 million cases or 9.4% higher than case sales of 313.4 million cases for the nine-months ended September 30, 2018. The overall average net sales per case (excluding net sales of AFF Third-Party Products of $17.0 million and $17.9 million for the nine-months ended September 30, 2019 and 2018, respectively, as these sales do not have unit case equivalents) increased to $9.24 for the nine-months ended September 30, 2019, which was 1.1% higher than the average net sales per case of $9.14 for the nine-months ended September 30, 2018. The increase in the average net sales per case was primarily attributable to a price increase effective from