or 17.5% of net sales for the six months ended November 30, 2017, versus pretax income of $61.7 million, or 17.1% of net sales, for the same period a year ago, reflecting leverage on 7.1% growth in net sales during the current period, combined with the benefit from the closure of an unprofitable European manufacturing facility and severance actions taken during fiscal 2017. As previously reported, an edible coatings patent expired in the U.S. during the month of August 2017, and as a result, we anticipate the impact of the patent expiration on fiscal 2018 IBT to approximate at least $10.0 million.
Income Tax Rate The effective income tax expense rate was 19.6% for the six months ended November 30, 2017 compared to an effective income tax benefit rate of 3.7% for the six months ended November 30, 2016.
For the six-month period ended November 30, 2017, the favorable variance from the 35% statutory rate is primarily due to a cumulative net $27.0 million discrete benefit recorded in the six-month period primarily related to the execution of certain tax planning strategies and a corresponding reduction to the deferred tax liability recorded for our estimate of the U.S. tax cost associated with unremitted foreign earnings that may be repatriated in the foreseeable future.
For the six-month period ended November 30, 2016, the variance from the 35% statutory rate is primarily due to an $11.3 million discrete tax benefit recorded for excess tax benefits related to equity compensation and the inflated effect of that rate benefit due to the relatively low level of pre-tax income.
Net Income Net income of $212.8 million for the six months ended November 30, 2017 compares to net income of $43.1 million for the comparable prior year period. Net income attributable to noncontrolling interests approximated $0.9 million and $1.3 million for the first half of fiscal 2018 and 2017, respectively. Net income attributable to RPM International Inc. stockholders for the first half of fiscal 2018 was $211.9 million, or 8.0% of consolidated net sales, which compared to net income of $41.8 million, or 1.7% of consolidated net sales for the comparable prior year period.
Diluted income per share of common stock for the six months ended November 30, 2017 of $1.56 compares with diluted earnings per share of common stock of $0.32 for the six months ended November 30, 2016.
LIQUIDITY AND CAPITAL RESOURCES
Approximately $115.2 million of cash was provided by operating activities during the first half of fiscal 2018, compared with $158.7 million of cash provided operating activities during the same period last year.
The net change in cash from operations includes the change in net income, which increased by $169.6 million during the first half of fiscal 2018 versus the same period during fiscal 2017. Changes in working capital accounts and all other accruals used approximately $52.0 million more cash flow during the first half of fiscal 2018 versus the same period last year.
The change in accounts receivable during the first half of fiscal 2018 provided approximately $76.7 million less cash than during the same period a year ago. Days sales outstanding at November 30, 2017 increased to 63.0 days from 59.5 days sales outstanding at November 30, 2016.
During the first half of fiscal 2018, we spent approximately $18.7 million less cash for inventory purchases compared to our spending during the same period a year ago. This resulted from the combination of timing of purchases by retail customers and a systematic reduction of inventory levels at certain businesses in our consumer segment. Days of inventory outstanding at November 30, 2017 decreased to 101.7 days from 102.5 days of inventory outstanding at November 30, 2016.
The change in accounts payable during the first half of fiscal 2018 used approximately $25.8 million more cash than during the first half of fiscal 2017, resulting principally from the timing of certain payments. Accrued compensation and benefits used approximately $10.2 million less cash during the first half of fiscal 2018 versus fiscal 2017, due to lower bonus accruals made during fiscal 2018 versus fiscal 2017. Other accruals and prepaids, including those for other short-term and long-term items and changes in accrued loss reserves, provided $22.5 million more cash during the first half of fiscal 2018 versus the same period a year ago, primarily from the timing of customer rebates.
Cash provided from operations, along with the use of available credit lines, as required, remain our primary sources of liquidity.
RPM International Inc. (NYSE: RPM) owns subsidiaries that are world leaders in coatings, sealants, building materials and related services. From homes to precious landmarks worldwide, their brands are trusted by consumers and professionals alike to protect, improve and beautify. Among its leading consumer brands are Rust-Oleum, DAP and Zinsser. Learn more about RPM brands >>
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