Sales were down 5.8%.
However, we saw gross profit margin of 43.4% expand 170 basis points and reported operating profit margin expand 180 basis points against the prior year.
I have been at Acuity Brands for a little over 12 months and what I continue to see every day is a team that is striving for success, that is not shy about changing and that believes in Acuity and where we are going.
Trevor brings 27 years of industry experience to the role.
Our recent accomplishment of achieving carbon neutrality across Scope 1 and 2 emissions in our operations is the result of this work and demonstrates our commitment to continually improving our communities.
As I previously mentioned, we have now repurchased nearly 10% of our outstanding shares since May 2020.
Our associates pulled together to deliver a solid performance and the fourth consecutive quarter of gross profit margin over 42%.
Moving to our second quarter results, net sales were $777 million, a decrease of 5.8% compared to the prior year, which we believe was a very good performance in this market.
Retail channel sales declined approximately 24% as compared to the prior year as a result of strong year-over-year pre-pandemic comparison.
Finally, sales in corporate accounts declined just over 50% as compared to the prior year.
Gross profit margin was 43.4% for the second quarter of fiscal 2021, an increase of 170 basis points over the prior year.
Given this gross profit margin improvement, we believe attaining a gross profit margin above 42% is reasonable on an annualized basis.
Reported operating profit margin was 11.7% of net sales for the second quarter of fiscal 2021, an increase of 180 basis points over the prior year.
Adjusted operating profit margin was 14% of net sales for the second quarter of fiscal 2021, an increase of 170 basis points over the prior year.
As previously discussed, this quarter, we were able to share with our associates that we achieved 100% carbon neutrality within our operations by prioritizing efficiency improvements in operations and some offsetting measures.
The effective tax rate for the second quarter of fiscal 2021 was 23.5% compared with 23.4% in the prior year quarter.
We currently estimate that our blended effective income tax rate will be around 24% for the full year fiscal 2021.
Diluted earnings per share of $1.74 increased $0.30 or 20.8% over the prior year and adjusted diluted earnings per share of $2.12 increased $0.28 or 15.2% over the prior year.
Net cash from operating activities for the first half of fiscal 2021 was relatively flat at approximately $213 million compared to the prior year.
We invested $21 million or 1.4% of net sales in capital expenditures during the first half of fiscal 2021 and currently expect to invest approximately 1.5% of net sales in capital expenditures in the full year of fiscal 2021.
On February 28, 2021, we had cash and cash equivalent balance of $499 million.
Over the last 12 months, we have been extremely judicious around our capital allocation decisions.
As a result, we have repurchased 3.2 million shares of common stock during the first half of fiscal 2021 for a total of $338.3 million, at an average price of $104 per share, with 4.4 million shares still remaining under our current Board authorization.
Whether commodity prices increase or decline, we believe we can hold gross profit margin above 42% by controlling what we can control and through the ongoing improvements throughout our business.

Summary:
Diluted earnings per share of $1.74 increased $0.30 or 20.8% over the prior year and adjusted diluted earnings per share of $2.12 increased $0.28 or 15.2% over the prior year.