Data shows that the U.S. remains the most valuable sports rights market in the world with an estimated $19.5 billion of annualized rights value last year.
In the second quarter, we renewed our Wimbledon U.S. media rights agreement with ESPN and its tennis channel until 2035 for a significant increase over the prior term.
Our last five renewals have yielded, on average, over 100% increases.
Sports wagering is now legal in 21 states and growing fast.
We also closed a deal for UFC and Panini to create NFT trading cards, the first release of which sold out in less than 24 hours.
The first half of 2021 saw median telecom M&A has reached their highest level in years, $83 billion.
The competition for content and talent is at its highest level I've seen in 26 years.
The number of original series and movies commissioned by streaming platforms grew 48% for the past four quarters as compared to prior four quarters.
Netflix alone revealed it will spend $17 billion on content in 2021, up 44%, compared to 2020.
For example, this past quarter alone, we've closed new podcast deals for 40 clients, while four client shows hit No.
1 on the Apple charts.
First, we announced during our last earnings call that we expected to pay down $600 million of debt in the third quarter, part of our continued commitment to reduce leverage.
For the quarter ended June 30, 2021, we generated approximately $1.1 billion in revenue, up $648 million or 140%.
Adjusted EBITDA for the quarter was approximately $168 million, up $122 million.
Our Owned Sports Properties segment continued to perform very well, with revenues of $258.9 million, an increase of $106.6 million or 70%.
Adjusted EBITDA for the quarter was $132.3 million, double that of the same period in 2020, primarily driven from the higher revenues I just mentioned.
More recently, our July UFC 264 event in Las Vegas finished at the second-highest gate in T-Mobile Arena history and the third-highest gate among UFC events of all time.
The event had more than 20,000 fans, the highest attendance ever recorded at a sporting event in T-Mobile.
Year over year, we've seen nearly 30% growth in the 18 to 24 demographic, and we're currently ranked third behind the NFL and NBA among millennials.
Partnership revenues is up over 25% versus 2020.
Lastly, as relates to viewership, UFC events, which are simulcast across the ESPN family, reached 18.3 million viewers on ESPN TV networks alone in the first half of this year, up 10% over last year.
This segment recorded revenue of $528.7 million, an increase of $408.8 million.
Adjusted EBITDA for the quarter was $36.8 million, up $79.5 million compared to Q2 2020, where we recorded a loss.
Revenue was $328.2 million, an increase of $135.4 million or just over 70%.
This growth was primarily driven by an increase in client commissions and project deliveries at Endeavor Content, including episodes of Season 2 of Truth Be Told for Apple TV, The Wall in NBC and Netflix film Blue Miracle.
That slight timing delay, predominantly from three shows, negatively impacted our revenues in the quarter by approximately $90 million.
Adjusted EBITDA for the quarter was $61.7 million, an increase of $9.6 million or just over 18% as we realized a higher percentage of revenue growth from Endeavor Content versus clients in the quarter.
Finally, corporate adjusted EBITDA for the quarter was a loss of $62.7 million, reflecting an increase in costs brought on to support increased activity and investment in the business, as well as those costs associated with being a new public company.
We paid down $600 million of our outstanding debt in Q2, which consisted of the repayment of approximately $163 million under the WME IMG revolving credit facility, which now carries a zero balance; $257 million, representing the entirety of the WME IMG term loan issued in May 2020, which was the highest cost paper in our capital structure; and $180 million of the first lien term loan under the UFC facilities.
Because of these moves, we will realize $35 million in annual interest savings going forward.
On to our updated guidance for the full-year 2021.
We are, therefore, raising our revenue guidance from a prior range of $4.76 billion and $4.83 billion to now between $4.8 billion and $4.85 billion.
And on adjusted EBITDA, we're raising the range from $735 million to $745 million to between $765 million and $775 million.

Summary:
For the quarter ended June 30, 2021, we generated approximately $1.1 billion in revenue, up $648 million or 140%.
On to our updated guidance for the full-year 2021.
We are, therefore, raising our revenue guidance from a prior range of $4.76 billion and $4.83 billion to now between $4.8 billion and $4.85 billion.
And on adjusted EBITDA, we're raising the range from $735 million to $745 million to between $765 million and $775 million.