We increased our head count in that business 12.4% year over year.
Revenue grew 12.9% with every segment reporting growth.
And we continued making investments in headcount, adding 346 total billable professionals year over year, including 36 senior managing directors.
Earnings per share were also boosted by FX remeasurement gains and lower weighted average shares outstanding, or WASO, resulting in a 45% increase in GAAP earnings per share and a 31% increase in adjusted earnings per share compared to the prior-year quarter.
Revenues of $702.2 million increased $80 million, compared to revenues of $622.2 million in the prior-year quarter.
GAAP earnings per share of $1.96 in 3Q '21 compared to $1.35 in 3Q '20.
Adjusted earnings per share for the quarter were $2.02, which compared to $1.54 in the prior-year quarter.
The difference between our GAAP and adjusted earnings per share in 3Q '21 reflects $2.4 million of noncash interest expense related to our convertible notes, which reduced GAAP earnings per share by $0.06 per share.
In 3Q of '20, we had a special charge of $7.1 million as well as noncash interest expense of $2.3 million, which reduced GAAP earnings per share by $0.14 per share and $0.05 per share, respectively.
Net income of $69.5 million, compared to $50.2 million in the prior-year quarter.
The increase in net income was primarily due to higher revenues, which was partially offset by an increase in compensation, including the impact of a 6.9% increase in billable headcount and higher SG&A expenses.
SG&A of $138.6 million or 19.7% of revenues.
This compares to SG&A of $122 million or 19.6% of revenues in the third quarter of 2020.
Third quarter 2021 adjusted EBITDA of $100.3 million or 14.3% of revenues, compared to $90.9 million or 14.6% of revenues in the prior-year quarter.
Our third quarter effective tax rate of 21.6% compared to 22.3% in the prior-year quarter.
Fully diluted WASO of 35.4 million shares in 3Q '21 compared to 37.1 million shares in 3Q '20.
Our convertible notes had a dilutive impact on earnings per share of approximately 842,000 shares, included in WASO, as our average share price of $138.83 this past quarter was above the $101.38 conversion threshold price.
As I mentioned, billable headcount increased by 346 professionals or 6.9% compared to the prior-year quarter.
In Corporate Finance & Restructuring, revenues of $250.3 million increased 5.8% compared to the prior-year quarter.
Adjusted segment EBITDA of $55.6 million or 22.2% of segment revenues compared to $56.2 million or 28 -- or 23.8% of segment revenues in the prior-year quarter.
The year-over-year decrease in adjusted segment EBITDA was due to increased compensation, including the impact of a 6% increase in billable headcount and higher SG&A expenses.
On a sequential basis, revenues increased $19.4 million or 8.4% as the segment benefited from continued growth in our business transformation and transactions businesses and recognition of prior deferred revenue.
Adjusted segment EBITDA for the third quarter increased $15.5 million.
Revenues of $145.3 million increased 22% relative to a weak quarter in the prior year.
Adjusted segment EBITDA of $16.6 million or 11.4% of segment revenues compared to $13.6 million or 11.4% of segment revenues in the prior-year quarter.
The increase in adjusted segment EBITDA was due to higher revenues, which was partially offset by higher compensation, which includes 7.7% growth in billable headcount as well as higher SG&A expenses compared to the prior-year quarter.
Sequentially, revenues decreased $5.5 million, primarily due to lower demand for investigations and health solutions services.
Adjusted segment EBITDA decreased $1.4 million.
Our Economic Consulting segment's revenues of $172.5 million increased 11.3% compared to the prior-year quarter.
Adjusted segment EBITDA of $29.9 million or 17.3% of segment revenues compared to $25.7 million or 16.6% of segment revenues in the prior-year quarter.
The increase in adjusted segment EBITDA was due to higher revenues, which was partially offset by higher compensation, which includes the impact of 5.1% growth in billable headcount.
Sequentially, revenues decreased $10.8 million or 5.9%, which was driven by decreased demand for M&A-related antitrust services, primarily due to the conclusion of a large matter in the quarter.
In Technology, revenues of $64.7 million increased 10.4% compared to the prior-year quarter.
Adjusted segment EBITDA of $7.8 million or 12.1% of segment revenues compared to $11.9 million or 20.4% of segment revenues in the prior-year quarter.
The decrease in adjusted segment EBITDA was due to higher compensation, which includes the impact of a 12.4% increase in billable headcount, as our Technology segment continues to make investments in talent, particularly at the senior levels to bolster our capacity and expertise globally across data risk, compliance, privacy and information governance, as well as higher SG&A expenses.
Sequentially, revenues decreased $14 million or 17.8%, primarily due to decreased demand for M&A-related second request services.
Adjusted segment EBITDA declined $10.7 million sequentially.
Record revenues in the Strategic Communications segment of $69.4 million increased 31.1% compared to the prior-year quarter.
Adjusted segment EBITDA of $15.5 million or 22.3% of segment revenues compared to $8.4 million or 15.9% of segment revenues in the prior-year quarter.
Sequentially, revenues increased $1.6 million, primarily due to higher demand for financial communications and corporate reputation services.
Adjusted segment EBITDA increased $2 million sequentially.
We generated net cash from operating activities of $196.9 million, which increased by $85.3 million compared to $111.6 million in the third quarter of 2020.
We generated free cash flow of $172.2 million in the quarter.
Total debt net of cash decreased $160.7 million sequentially from $159.4 million on June 30, 2021 to a negative net debt position of $1.3 million on September 30, 2021.
In light of our record financial performance during the first nine months of 2021, we are raising the low end of our previous full year 2021 guidance range for revenues of between $2.7 billion and $2.8 billion to expected revenues of between $2.75 billion and $2.8 billion.
We are raising our full year 2021 guidance ranges for GAAP earnings per share of between $5.89 and $6.39 and adjusted earnings per share of between $6 and $6.50 to GAAP earnings per share of between $6.39 and $6.64 and adjusted earnings per share of between $6.50 and $6.75.
The $0.11 per share variance between earnings per share and adjusted earnings per share guidance for full year 2021 includes the estimated impact of noncash interest expense of $0.20 per share related to our 2023 convertible notes and the second quarter 2021 $0.09 per share gain related to the fair value remeasurement of acquisition-related contingent consideration, which are not included in adjusted EPS.
As credit markets remain in an accommodative mode and the number of stressed and distressed issuances remains low, Standard & Poor's is now forecasting that the trailing 12-month U.S. speculative rate -- default rate -- corporate default rate will fall further in the first half of 2022, reaching 2.5% by June 2022, which compares to 3.8% in June 2021 and 6.6% in January 2021.
Business transformation and transaction services, which represented 36% of total segment revenues in Corporate Finance in Q3 of last year, contributed 59% this quarter.
Non-M&A-related antitrust services have steadily grown to represent 32% of our Economic Consulting revenues this quarter, which compares to 23% in Q3 of last year.
Our Australian business has grown to 31 senior managing directors from 19 two years back.
And our Middle East business has grown to 16 senior managing directors from five two years back.
And EMEA represented 30% of revenues this quarter with us only recently ramping up in Germany and Spain.

Summary:
Revenues of $702.2 million increased $80 million, compared to revenues of $622.2 million in the prior-year quarter.
GAAP earnings per share of $1.96 in 3Q '21 compared to $1.35 in 3Q '20.
Adjusted earnings per share for the quarter were $2.02, which compared to $1.54 in the prior-year quarter.
We are raising our full year 2021 guidance ranges for GAAP earnings per share of between $5.89 and $6.39 and adjusted earnings per share of between $6 and $6.50 to GAAP earnings per share of between $6.39 and $6.64 and adjusted earnings per share of between $6.50 and $6.75.