This will be followed by an activity rebound in the second quarter and further acceleration of growth in the second half of the year, particularly in the international markets. This will support the ambition we have set for the full year revenue and earnings growth. I will now turn the call over to Stephane.
Stephane Biguet : Thank you, Olivier, and good morning, ladies and gentlemen. Fourth quarter earnings per share, excluding charges and credits was $0.86. This represents an increase of $0.08 sequentially and an increase of $0.15 when compared to the same period of last year. We recorded $0.09 of charges during the fourth quarter of this year, $0.06 related to the devaluation of the peso in Argentina and the remaining $0.03 related to merger and integration costs associated with our acquisition of the Aker subsea business, which closed at the beginning of the quarter. We anticipate that we will incur additional charges as integration activities continue over the course of 2024. Our full year 2023 revenue of $33.1 million grew 18% year-on-year.
While this revenue is roughly the same as the pre-pandemic level of 2019, our adjusted EBITDA in 2023 in absolute dollars was 22% higher. As a result, our full-year 2023 EBITDA margin of 24.5% has expanded 430 basis points over this period on a similar revenue base. This highlights the high grading of our portfolio over the last few years, our significantly improved operating leverage and our favorable market position, particularly internationally and offshore. Fourth quarter revenue of $8.99 billion increased 8% sequentially, with the acquired of Aker subsea business accounting for approximately 70% of the increase. Fourth quarter pretax operating margin of 20.8% improved 52 basis points sequentially and 101 basis points year-on-year. Adjusted EBITDA margin for the fourth quarter of 25.3% was 95 basis points higher than the same period of last year.
I will now go through the fourth quarter results for each division. Fourth quarter digital and integration revenue of $1 billion increased 7% sequentially, with pretax operating margin expanding 197 basis points to 34%. This growth was due to increased digital revenue across all areas, led by the Middle East and Asia and Europe and Africa. Reservoir Performance revenue of $1.7 million grew 3% sequentially, primarily due to increased activity internationally, mainly in the Middle East and Africa. Pretax operating margin increased 88 basis points to 21.4%, representing the highest level of this cycle, driven by higher activity and improved pricing. While construction revenue of $3.4 billion was essentially flat sequentially as international growth of 2% was offset by a decline in North America revenue resulting from lower U.S. land rig count.
Pretax operating margin increased 35 basis points sequentially. Lastly, Production Systems revenue of $2.9 billion increased 24% sequentially, largely due to the acquired Aker subsea business. Excluding this effect, revenue grew 4% sequentially due to strong international sales. Pretax operating margin expanded 153 basis points to 15%, its highest-level this cycle on higher sales of midstream, artificial lift and subsea production systems. Looking ahead to the full year of 2024. We expect continued margin expansion in our core, driven by sustained operating leverage, a favorable geographic mix and pricing tailwinds. In our Digital and Integration division, we expect margins to remain approximately at the same level as 2023 as digital margins will increase due to the accelerated adoption of our new technology platforms, while APS margins will decrease as a result of higher amortization expenses.
All in all, as mentioned by Olivier, strong year-on-year revenue growth and continued margin expansion will result in adjusted EBITDA growth in the mid-teens in 2024 when compared to 2023. Now turning to our liquidity. We generated $3 billion of cash flow from operations and $2.3 billion of free cash flow during the fourth quarter. This exceptional performance resulted in full year free cash flow of $4 billion, which is the highest level we have achieved since 2015. This was due to a combination of very strong year-end receivable cash collections, increased customer advances, improved inventory turns and the receipt of the prior year tax returns. As a result of this exceptional free cash flow performance, we reduced our net debt by $1.4 billion during the quarter to $8 billion.
This represents our lowest net debt level since the first quarter of 2016. Capital investments, including CapEx and investments in APS projects and exploration data were $742 million in the fourth quarter and $2.6 billion for the full year. Looking ahead, we will continue to be disciplined as it relates to our capital investments. Despite the continued revenue growth, our 2024 capital investments will remain at approximately the same level as in 2023. Finally, during the fourth quarter, we repurchased 1.8 million shares of our stock for a total purchase price of $100 million. For the full year, we returned a total of $2 billion to shareholders in the form of dividends and stock repurchases. Our continued capital discipline, combined with the confidence we have that 2024 will be another year of strong cash flow generation, which enable us to increase our returns to shareholders in 2024.
In this regard, when combining the increased quarterly dividend that we announced today, with increased share repurchases, we are targeting to return more than $2.5 billion to our shareholders in 2024. I will now turn the conference call back to Olivier.
Olivier Le Peuch : Thank you, Stephane. Ladies and gentlemen, I think we will start the Q&A. So Leah, back to you.
Operator: [Operator Instructions] And first, we go to the line of James West with Evercore ISI.
James West: So Olivier, curious to hear your thoughts. Clearly, you’re looking for another year of pretty strong growth in EBITDA and revenue. But it seems to me like we’ve got a lot of particularly deepwater rigs that are going to start turning to the right here very soon and particularly in the second half, and it’s — there should be an exit rate that’s even higher than that type of growth as we go into ’25. I think, is that a fair assumption, or am I getting ahead of my skews here in terms of kind of what the overall market opportunity is going to be as we step through this year and get into the ’25, ’26 period?
