adoption of the standard was a net decrease of $0.9 million and $2.4 million during the three and nine months ended June 30, 2019, respectively.
Our Brooks Semiconductor Solutions Group segment reported revenue of $116.0 million for the three months ended June 30, 2019 compared to $122.7 million for the corresponding period of the prior fiscal year, a decrease of $6.6 million, or 5%. We reported a decline in automation systems revenue of $13.0 million and services revenue of $1.0 million, which were partially offset by an increase in contamination control systems of $7.3 million. For the nine months ended June 30, 2019, our Brooks Semiconductor Solutions Group segment reported revenue of $341.6 million compared to $326.2 million for the corresponding period of the prior fiscal year, an increase of $15.4 million, or 5%. We reported an increase in contamination control solutions of $35.7 million, of which $15.1 million is attributable to six additional months of revenue for the acquisition of Tec-Sem, acquired on April 1, 2019, this was partially offset by declines in automation systems of $19.1 million and services of $1.2 million. The semiconductor markets are cyclical and may fluctuate significantly from quarter to quarter. Demand for our Brooks Semiconductor Solution Group products is affected by these cycles. The difference in reported revenue due to the adoption of the new revenue recognition standard was a net increase of $0.2 million and $0.8 million for the three and nine months ended June 30, 2019, respectively.
Our Brooks Life Sciences segment reported revenue of $87.8 million for the three months ended June 30, 2019 compared to $49.7 million for the corresponding period of the prior fiscal year. The increase of $38.1 million, or 77%, was composed of $37.1 million from acquisitions, and $1.1 million from internal growth, driven by increases in sales of BioStoreTM III Cryostores, sample storage services, infrastructure services, and consumables and instruments, partially offset by declines in automated cold storage systems. For the nine months ended June 30, 2019, our Brooks Life Sciences segment reported revenue of $240.0 million, compared to $145.7 million for the corresponding period of the prior fiscal year. The increase of $94.3 million, or 65% was composed of $86.3 million from acquisitions, and $8.0 million from internal growth, principally in sample storage services, consumables and instruments, infrastructure services, and BioStoreTM III Cryostores, partially offset by declines in automated cold storage systems and informatics solutions. The difference in reported revenue due to the adoption of the new revenue recognition standard was a net decrease of $1.0 million and $3.3 million during the three and nine months ended June 30, 2019, respectively.
Revenue generated outside the United States was $115.7 million, or 57% of total revenue, for the three months ended June 30, 2019 compared to $110.7 million, or 64% of total revenue, for the corresponding period of the prior fiscal year. Revenue generated outside the United States was $342.4 million, or 59% of total revenue, for the nine months ended June 30, 2019 compared to $298.0 million, or 63% of total revenue, for the corresponding period of the prior fiscal year. We had no customers that accounted for 10% or more of our consolidated revenue for each of the three and nine months ended June 30, 2019 and 2018.
Gross Margin
We reported gross margins of 41.0% for the three months ended June 30, 2019 compared to 38.8% for the corresponding period of the prior fiscal year. Gross margin increased in the Brooks Life Sciences Segment by 3.6 percentage points and in the Brooks Semiconductor Solutions Group segment by 1.6 percentage points in the 2019 period over the 2018 period. We reported gross margins of 40.6% for the nine months ended June 30, 2019 compared to 38.9% for the corresponding period of the prior fiscal year. Gross margin increased in the Brooks Life Sciences segment by 3.7 percentage points and in the Brooks Semiconductor Solutions Group by 0.1 percentage points in the 2019 period over the 2018 period. Cost of revenue for the three and nine months ended June 30, 2019 also included $0.0 million and $0.2 million, respectively, of charges related to the inventory step-up in purchase accounting, as compared to $0.7 million and $1.9 million, respectively, during the corresponding periods of the prior fiscal year. Excluding the purchasing accounting impact related to inventory step-up and the amortization of completed technology, gross margins expanded 2.3 percentage points and 1.9 percentage points, respectively, during the three and nine months ended June 30, 2019 as compared to the corresponding periods of the prior fiscal year. The difference in reported gross margin due to the adoption of the new revenue recognition standard was a net decrease in gross profit of $0.4 million and $0.9 million during three and nine months ended June 30, 2019, respectively.
Our Brooks Semiconductor Solutions Group segment reported gross margins of 40.9% for the three months ended June 30, 2019 as compared to 39.3% for the corresponding period of the prior fiscal year. The increase is driven by