Client engagement with our experts rose significantly, during Q3 client interactions increased more than 20% year-over-year to over 120,000 interaction.
More than 15,000 executives attended and that's about double the number that attended Orlando Symposium in-person last year.
Attendees were highly engaged and participated in an average of 11 live sessions.
More than 80% of IT Symposium Americas attendees rated the conference as meeting or exceeding their expectations.
We have eight more virtual conferences planned for 2020 and have -- already have more than 21,000 attendees registered.
Third quarter revenue was $995 million, down 1% both as reported and FX neutral.
Excluding conferences, our revenues were up 5% year-over-year FX neutral.
In addition, contribution margin was 67%, up more than 300 basis points versus the prior year.
EBITDA was $168 million, up 20% year-over-year and up 19% FX neutral.
Adjusted earnings per share was $0.91 and free cash flow in the quarter was a very strong $229 million.
Research revenue in the third quarter grew 6% year-over-year on a reported and FX neutral basis.
Third quarter research contribution margin was 72%, benefiting in part from the temporary cost avoidance initiatives we put in place starting in the first quarter.
Total contract value was $3.4 billion at September 30th, representing FX neutral growth of 5% versus the prior year.
Global Technology Sales contract value at the end of the third quarter was $2.8 billion, up 5% versus the prior year.
Client retention for GTS was 80%, down about 160 basis points year-over-year, but up modestly from last quarter.
Wallet retention for GTS was 99% for the quarter, down about 600 basis points year-over-year.
GTS new business declined 7% versus last year.
We ended the third quarter with enterprises down about 3% from last year.
It now stands at $227,000 per enterprise in GTS, up 9% year-over-year.
At the end of the third quarter, the number of quota-bearing associates in GTS was down about 8% year-over-year.
We expect to end 2020 with more than 3,100 quota-bearing associates, a slight decline from the end of 2019.
For GTS, the year-over-year net contract value increase, or NCVI, divided by the beginning period quota-bearing headcount was $41,000 per salesperson, down about 60% versus the third quarter of last year.
Despite the challenging macro environment, GTS CV grew in nearly all of our 10 largest countries similar to last quarter was up double digits in Brazil, Japan, France and the Netherlands.
Global Business Sales contract value of $656 million at the end of the third quarter.
That's about 20% of our total contract value.
CV growth was 6% year-over-year as reported and 5% on an organic basis.
All practices positively contributed to the 6% CV growth rate for GBS with the exception of marketing.
GBS new business was strong, up 14% over last year.
GxL is now more than 50% of GBS total contract value, an important milestone in the path to long-term sustained double-digit growth in GBS.
Client retention for GBS was 82%, up 117 basis points year-over-year.
Wallet retention for GBS was 99% for the quarter, up 220 basis points year-over-year.
We ended the third quarter with GBS enterprises down about 9% from last year as we continue to see churn of legacy clients.
The average contract value per enterprise continues to grow, it now stands at $140,000 per enterprise in GBS, up 16% year-over-year.
At the end of the third quarter, the number of quota-bearing associates in GBS was down 7% year-over-year.
For GBS, the year-over-year net contract value increase, or NCVI, divided by the beginning period quota-bearing headcount was $38,000 per salesperson, up from last year.
Conferences revenue for the quarter was $30 million, a combination of the two virtual conferences and a number of virtual Evanta meetings.
Third quarter consulting revenues decreased by 4% year-over-year to $89 million, on an FX neutral basis revenues declined 6%.
Consulting contribution margin was 32% in the third quarter, up over 300 basis points versus the prior-year quarter.
Labor-based revenues were $74 million, down 5% versus Q3 of last year or 6% on an FX neutral basis.
Labor-based billable headcount of 737 was down 9%.
Utilization was 60%, up about 300 basis points year-over-year.
Backlog at September 30th was $96 million, down 12% year-over-year on an FX neutral basis.
Our contract optimization business was down 3% on a reported basis versus the prior year quarter.
This compares to a 74% growth rate in the third quarter last year.
SG&A increased 2% year-over-year in the third quarter and 1% on an FX neutral basis.
EBITDA for the third quarter was $168 million, up 20% year-over-year on a reported basis and up 19% FX neutral.
Depreciation in the quarter was up approximately $2 million from last year, although, flat with the second quarter as a result of additional office space that had gone into service before the pandemic hit.
Net interest expense, excluding deferred financing costs in the quarter, was $29 million, up from $22 million in the third quarter of 2019.
The Q3 adjusted tax rate which we use for the calculation of adjusted net income was 20% for the quarter.
The tax rate for the items used to adjusted net income was 26.4% in the quarter.
Adjusted earnings per share in Q3 was $0.91.
Operating cash flow for the quarter was $244 million compared to $220 million last year.
Capex for the quarter was $15 million, down 59% year over year.
Free cash flow for the quarter was $229 million, which is up 25% versus the prior year.
This includes outflows of about $10 million of acquisition, integration and other non-recurring items.
Free cash flow as a percent of revenue, or free cash flow margin was 15% on a rolling four-quarter basis, continuing the improvement we've been making over the past few years.
Free cash flow as a percent of GAAP net income was about 285%.
While we've seen timing benefits to our free cash flow margin from significantly lower capex and our ability to defer certain tax payments, even excluding these, LTM free cash flow margin is still up about 200 basis points versus the prior year.
During the quarter, we took advantage of historically attractive high yield bond pricing and issued $800 million of new 10-year senior unsecured notes with a 3.75% coupon.
We use the proceeds from this new issuance to extinguish our 2025 bonds, which carry a 0.625% coupon.
The overall impact of the financing activities resulted in a 50 basis point reduction to total cost of borrowing.
Our September 30th debt balance was $2 billion.
Our reported gross debt to trailing 12 month EBITDA is about 2.5 times.
Our total modified net debt covenant leverage ratio was 2.3 times at the end of the third quarter, well within the 5 times covenant limit.
At the end of the third quarter, we had $554 million of cash.
At the end of the quarter, we had about $1 billion of revolver capacity and have around $680 million remaining on our share repurchase authorization.
We now forecast research revenue of at least $3.57 billion for the full year.
This is growth of almost 6% versus 2019 and reflects a continuation of third quarter new business and retention trends.
We now expect revenue of $110 million for the full year.
We now forecast consulting revenue of at least $370 million for the full year or a decline of about 6%.
Overall, we expect consolidated revenue of at least $4.05 billion, that's a reported decline of about 5% versus 2019.
Excluding conferences, we expect revenue growth of at least 4.5% versus 2019 on a reported basis.
We expect full year adjusted EBITDA of at least $740 million, that's full year margins of about 18.3%, up from the 16.1% margins we had in 2019.
We expect our full year 2020 net interest expense to be $106 million.
We continue to expect an adjusted tax rate of around 22% for 2020.
We expect 2020 adjusted earnings per share of at least $4.07.
For 2020, we expect free cash flow of at least $625 million.

Summary:
Third quarter revenue was $995 million, down 1% both as reported and FX neutral.
Adjusted earnings per share was $0.91 and free cash flow in the quarter was a very strong $229 million.
Adjusted earnings per share in Q3 was $0.91.
We now expect revenue of $110 million for the full year.
We expect 2020 adjusted earnings per share of at least $4.07.
For 2020, we expect free cash flow of at least $625 million.