We quickly mobilized our supply chain and global operations to address and support ventilation needs worldwide, producing over 150,000 ventilators.
We accelerated the production and distribution of noninvasive and life support ventilators and mass systems to those in need, resulting in an incremental $35 million of COVID-related revenue during the March 2020 quarter.
We see a range of -- from 70% of pre-COVID patient flow in some countries, up to 90% of pre-COVID patient flow in other countries.
Excluding the $35 million of COVID-related ventilator sales in the March 2020 quarter, our team delivered positive sales growth across our core sleep apnea and respiratory care business this quarter on both the headline and constant-currency basis.
In the June 2020 quarter, we recognized $125 million in COVID-related ventilator sales.
And in September 2020 quarter, we recognized $40 million in such revenue.
Our headline results were impacted this quarter by an accounting reserve we took in connection with discussions with the Australian Tax Office, or ATO, regarding their ongoing audit dating back to fiscal-year 2009.
I will make this statement: ResMed pays significant taxes in countries around the world, and we operate in over 140 countries, helping people sleep better, breathe better and live better lives well away from the hospital.
Brett and his team are working toward a final resolution of these transfer pricing discussions dating back over 12 years with the ATO.
So we have taken this $255 million reserve.
During the third quarter of fiscal-year 2021, we generated over $196 million in operating cash, allowing us to return $57 million in cash dividends to shareholders.
We are the clear leader in this field with over 14 million cloud-connectable medical devices in the market.
We have an exciting pipeline of innovative solutions that will generate both medium and long-term value, with an industry-leading IP portfolio, including over 8,000 patents and designs.
We now have over 8.5 billion nights of respiratory medical data in our cloud-based platform called Air Solutions.
We have over 15.5 million patients enrolled in our cloud-based AirView software solution.
And we also have over 105 million patients managed within our Software-as-a-Service network for out-of-hospital healthcare.
During 2020, an important 30-year duration study was published in the European Respiratory Journal, following over 4,500 diagnosed OSA patients to better understand the long-term impacts of untreated sleep apnea.
The study showed that untreated sleep apnea leads to high incidence of myocardial infarction or heart attack, high incidence and prevalence of Type 2 diabetes, and high incidence of ischemic heart disease.
So for every additional hour of positive airway pressure use, there was an 8% decrease in hospital inpatient visits and a 4% decrease in overall physician visits.
In our core market of sleep apnea, we continue to see sequential improvement in new patient diagnosis trends as we seek to provide solutions for the 936 million people worldwide who suffocate every night.
And we expect to see this improve over time in our portfolio of 140 country markets each quarter.
regulatory filings that we made for our next-generation flow generator platform called the AirSense 11.
Earlier this month, we started a limited controlled product launch of the AirSense 11 in certain parts of the United States.
For now, I can say that as a personal user of our CPAP therapy, I have firsthand knowledge that the AirSense 11 device will benefit patients and their bed partners.
Let me turn now to a discussion of our respiratory care business, focusing on our strategy to better serve the 380 million COPD, or chronic constructive pulmonary disease, patients and the 340 million asthma patients worldwide.
Over the past 12 months, COVID-19 has had a dampening effect on elective and emergent procedures at hospitals, as we all know, and that has slowed hospital discharge rates affecting patient flow and ultimately, the census rates at skilled nursing facilities, home health, hospice and beyond.
With over 1.5 billion people around the world suffering from sleep apnea, COPD, and asthma combined, we see incredible opportunities for greater identification, enrollment, and engagement of people with our digital health pathways.
We are relentlessly driving innovation and development to provide the scale needed to expand the impact of this technology across the 140 countries that we operate in.
Before I hand the call over to Brett for his remarks, I want to, once again, express my sincere gratitude for the more than 7,500 ResMedians for their perseverance, hard work, and dedication during these most unusual circumstances these last 15 months.
Group revenue for the March quarter was $769 million, which is consistent with the prior-year quarter.
In constant-currency terms, revenue decreased by 3% compared to the prior-year quarter.
Consistent with our prediction during the Q2 earnings call, we derived negligible incremental revenue from COVID-19-related demand in the March quarter, whereas our prior-year Q3 revenue included an incremental benefit from COVID-19-related sales of approximately $35 million.
Excluding these impacts, our Q3 FY '21 revenue increased by 1% in constant-currency terms.
Taking a close look at our geographic distribution and excluding revenue from our Software-as-a-Service business, our sales in U.S., Canada, and Latin America countries were $403 million, an increase of 2%.
Sales in Europe, Asia, and other markets totaled $272 million, a decrease of 5% or a decrease of 13% in constant-currency terms.
By product segment, U.S., Canada, and Latin America device sales were $193 million, a decrease of 2%.
Masks and other sales were $210 million, an increase of 7%.
In Europe, Asia, and other markets, device sales totaled $173 million, a decrease of 11% or in constant-currency terms, an 18% decrease.
Masks and other sales in Europe, Asia, and other markets were $99 million, an increase of 9% or flat year over year in constant-currency terms.
Globally, in constant-currency terms, device sales decreased by 10%, while masks and other sales increased by 4%.
Excluding the impact of COVID-19-related sales in the prior-year quarter, global device sales declined by 3% in constant-currency terms, while masks and other sales increased by 6% in constant-currency terms.
Software-as-a-Service revenue for the third quarter was $94 million, an increase of 5% over the prior-year quarter.
Our non-GAAP gross margin decreased by 40 basis points to 59.6% in the March quarter, compared to 60% in the same quarter last year.
Our SG&A expenses for the third quarter were $160 million, a decrease of 7%, or in constant-currency terms, SG&A expenses decreased by 11% compared to the prior-year period.
SG&A expenses, as a percentage of revenue, improved to 20.9%, compared to the 22.4% we reported in the prior-year quarter, benefiting from cost management and reduced travel as a result of COVID-19 restrictions.
R&D expenses for the quarter were $56 million, an increase of 9%, on a constant-currency basis, an increase of 3%.
R&D expenses as a percentage of revenue was 7.3%, compared to 6.7% in the prior year.
Total amortization of acquired intangibles was $18 million for the quarter and stock-based compensation expense for the quarter was $16 million.
Our non-GAAP operating profit for the quarter was $242 million, an increase of 2%, reflecting well-contained operating expenses.
For the March quarter, we estimated and recorded an accounting tax reserve of $255 million, which is net of credits and deductions for a proposed settlement of transfer pricing audits by the Australian Taxation Office, or ATO.
The audit covered tax years 2009 to 2018.
As previously disclosed, for 2009 to 2013, the ATO issued assessment of $266 million, inclusive of penalties and interest.
As a result of recording the reserve, on a GAAP basis, our effective tax rate for the March quarter was 136%.
While on a non-GAAP basis, which excludes the reserve, our effective tax rate for the quarter was 19.4%.
Looking forward, we estimate our underlying non-GAAP FY '21 effective tax rate will be in the range of 17% to 19%.
Our non-GAAP net income for the quarter was $190 million, an increase of 1%.
Non-GAAP diluted earnings per share for the quarter were $1.30, an increase of 1%.
As a result of the tax reserve recorded this quarter, our GAAP net loss for the quarter was $78 million and our GAAP diluted loss per share for the quarter was $0.54.
Cash flow from operations for the quarter was $196 million, reflecting solid underlying earnings, partially offset by increases in working capital.
Capital expenditure for the quarter was $26 million.
Depreciation and amortization for the March quarter totaled $40 million.
During the quarter, we paid dividends of $57 million.
We recorded equity losses of $5 million in our income statement in the March quarter associated with the Verily joint venture.
And going forward, we expect to record equity losses in the range of $3 million to $5 million per quarter associated with the Verily joint venture.
We ended the third quarter with a cash balance of $231 million.
At March 31, we had $734 million in gross debt and $503 million in net debt.
And at March 31, we had a further $1.5 billion available for drawdown under our existing revolver facility.
Our board of directors today declared a quarterly dividend of $0.39 per share, reflecting the board's confidence in our strong liquidity position and operating performance.
As a reminder, we recorded $35 million COVID-19 generated revenue in our March quarter last year, $125 million in our June quarter last year, and $40 million in our first quarter of FY '21.

Summary:
In constant-currency terms, revenue decreased by 3% compared to the prior-year quarter.
Non-GAAP diluted earnings per share for the quarter were $1.30, an increase of 1%.
As a result of the tax reserve recorded this quarter, our GAAP net loss for the quarter was $78 million and our GAAP diluted loss per share for the quarter was $0.54.