Contract drilling services revenues for the fourth quarter totaled $195 million compared to $227 million in the third quarter of 2020.
The decrease in revenues was due largely to a lower dayrate on the Noble Lloyd Noble and lower operating days on the Noble Tom Prosser and Noble Clyde Boudreaux in the fourth quarter. Marketed fleet utilization was 70% in the fourth quarter compared to 72% in the third quarter.
For the full year 2020, operating days declined by 19% compared to 2019, driven by lower utilization on a number of rigs including the Bully II, Noble Scott Marks, Noble Sam Turner, Noble Hans Deul, and Noble Joe Beall.
Contract drilling services costs for the fourth quarter were $125 million compared to $137 million in the third quarter of 2020. The 9% decline from third quarter was primarily driven by the disposition of the five cold-stacked rigs, and lower expenses on rigs that were idle during the fourth quarter. Contract drilling margin decreased to 36 percent from 40 percent in the previous period.
Adjusted EBITDA for the fourth quarter was $57 million compared to $76 million in the third quarter. For the full year 2020, Adjusted EBITDA totaled $281 million versus $329 million for the full year 2019.
On July 31, 2020, Legacy Noble and certain of its subsidiaries (collectively, the "Debtors") commenced voluntary cases under chapter 11 of title 11 of the United States Code (the "Chapter 11 Cases") in the United States Bankruptcy Court for the Southern District of Texas. On February 5, 2021, the Debtors emerged from the Chapter 11 Cases with a new parent company organized under the laws of the Cayman Islands named Noble Corporation.
Noble is adopting fresh start accounting as of the date of emergence, which will result in a new reporting entity and include adjustments for reporting periods after the emergence date. Accordingly, because fresh start accounting rules apply, our financial condition and results of operations following emergence from the Chapter 11 Cases will not be comparable to the financial condition and results of operations reflected in our historical financial statements from before February 5, 2021.
As a result of the financial restructuring, Noble emerged with a substantially delevered balance sheet with less than $300 million of net debt and liquidity of over $600 million. Noble's new capital structure includes a new $675 million revolving credit facility, of which $178 million is currently drawn, and $216 million of second lien notes.
At emergence, Legacy Noble's ordinary shares were cancelled and shares of the Company were issued to Legacy Noble's former bondholders. Certain former bondholders and former equity holders of Legacy Noble were also issued warrants to purchase shares of the Company. The Company intends to pursue listing on a national securities exchange. ■