In a challenging global supply chain environment, we grew sales 11% and expanded our gross profit and operating profit margins.
We have made significant progress by reaching carbon neutrality in our operations and by committing to the reduction of 100 million metric tons of carbon from our put in place products and services by 2030.
We have the talent and the tools to build upon the operating strength we have developed over the last 18 months.
Net sales were $192 million, an increase of 11% compared to the prior year.
This performance was driven by strong customer demand, improved execution across our go-to-market channels, and the addition of the OSRAM acquisition, which added approximately 200 basis points.
Gross profit margin was 42.2% for the fourth quarter of fiscal 2021, an increase of 10 basis points over the prior year, despite rising costs from raw materials, electrical component supply chain interruptions and a significant escalation of freight costs.
Reported operating profit margin was 13.4% of net sales for the fourth quarter of fiscal 2021, an increase of 150 basis points over the prior year.
Adjusted operating profit margin was 15.8% of net sales for the fourth quarter of fiscal 2021, an increase of 110 basis points over the prior year.
The effective tax rate for the fourth quarter of fiscal 2021 was 21.9% compared with 24.5% in the prior year due to the impact of several discrete items.
Diluted earnings per share of $2.72, increased $0.85 or 46% over the prior year and adjusted diluted earnings per share of $3.27 increased $0.92, or 39% over the prior year.
Our share repurchase program favorably impacted diluted earnings per share by $0.24 versus the prior year.
Net sales were $3.5 billion, an increase of 4% compared to the prior year, driven by improved sales performance in the second half of 2021.
We delivered a full year gross profit margin of 42.6%, an increase of 40 basis points over the prior year.
Reported operating profit margin was 12.4% of net sales for fiscal 2021, an increase of 180 basis points over the prior year with adjusted operating profit margin at 14.6% for fiscal 2021, an increase of 90 basis points over the prior year.
The effective tax rate for fiscal 2021 was 22.7% compared with 23.5% in the prior year.
We expect this rate to be approximately 23% for the full year in fiscal 2022, excluding any unusual or discrete items and assuming no change to the corporate tax rate.
Diluted earnings per share of $8.38, was 34% increase over the prior year and adjusted diluted earnings per share of $10.17 was a 23% increase over the prior year.
We had 36.6 million diluted shares outstanding during fiscal 2021, with our share repurchase program favorably impacting diluted earnings per share by $0.07 versus the prior year.
During the quarter, the Lighting and Lighting Controls segment delivered a sales increase of 11% versus the prior year.
This was driven by improvements within our independent sales network, which grew approximately 10% and the direct sales network, which grew about 15% in the current quarter as a direct result of our strong go-to-market efforts as well as recovery in the construction market.
Our corporate accounts channel continued the positive momentum and saw an increase in sales of 16% compared to the prior year, as large retailers move forward with previously deferred renovation spend.
Sales in the retail channel declined approximately 20% as compared to the prior year and will continue to be impacted through the remainder of the calendar year as a result of a customer inventory rebalancing.
The acquisition contributed around 200 basis points of growth to ABL revenue and we expect a similar level of impact in 2022.
Now moving to ABL operating profit for the fourth quarter of 2021, which increased 23% to $149 million versus $122 million in the prior year, with operating profit margin improving 150 basis points to 15.8%.
Adjusted operating profit for the fourth quarter of 2021 improved 21% versus the prior year with adjusted operating profit margin improving 140 basis points to 16.8%.
To summarize the full year the ABL business saw sales growth of 3% to $3.3 billion versus the prior year and an improvement across profitability metrics.
Operating profit for the full year increased 12% to $476 million versus the prior year with operating profit margin improving 110 basis points to 14.5%.
Adjusted operating profit for fiscal 2021 improved 10% to $515 million versus the prior year and adjusted operating profit margin improved 100 basis points to 15.7%.
For the fourth quarter of 2021 sales in spaces increased approximately 24% to $51 million, reflecting continued demand with strength across our building and HVAC controls.
Spaces operating profit for the fourth quarter of 2021 increased $3.6 million to $2 million versus the prior year.
Adjusted operating profit for the fourth quarter of 2021 of $6 million was $3.9 million greater than the prior year as a result of continued sales growth.
The team ended fiscal 2021 with sales growth of 21% to $190 million versus the prior year.
Operating profit increased $13.8 million to $9.9 million versus the prior year and operating profit margin of 5.2% for fiscal 2021 improved 770 basis points versus the prior year, with adjusted operating profit margin improving 400 basis points to 13.5%.
The net cash from operating activities for fiscal 2021 was $409 million.
This was a decrease of $96 million or 19% compared to the prior year, largely due to the increase in working capital needed to support the higher level of sales.
We invested $44 million or 1.3% of net sales in capital expenditures during fiscal 2021 and we continue to believe that capital expenditures of around 1.5% of net sales is an appropriate annual level as we head into 2022.
During the year, we repurchased approximately 3.8 million shares of common stock for $435 million at an average price of $114 per share.
We have around 3.8 million shares still remaining under our current Board authorization.
We expect 42% plus annualized gross profit margin for the full year of 2022.

Summary:
Diluted earnings per share of $2.72, increased $0.85 or 46% over the prior year and adjusted diluted earnings per share of $3.27 increased $0.92, or 39% over the prior year.