Brian Schell
Analyst · RBC Capital Markets
Thanks, Rahul, and good day, everyone. As noted in our press release, our Q1 24 GAAP results reflect revenues of [ $1.35 billion ], net income of $158 million and diluted earnings per share of $0.62. And as Bill noted earlier in the call, our adjusted revenues were a quarterly record $1.436 billion, up 5.3%, and adjusted diluted EPS was $1.28, up 12.3% and versus Q1 '23.
Adjusted diluted EPS includes $0.03 in dividend income received on investments previously excluded from adjusted earnings. Going forward, reported adjusted diluted EPS and guidance will include dividend income.
The adjusted revenue quarterly increase of $72 million was primarily driven by incremental revenue contributions from alternatives and Intralinks. Acquisitions contributed $3 million and foreign exchange had a favorable impact of $6 million. As a result, adjusted organic revenue growth on a constant currency basis was 4.7%. Our core expenses increased 1.9% or $16 million excluding acquisitions and on a constant currency basis.
Adjusted consolidated EBITDA attributable to SS&C, defined in Note 3 in the earnings release was $557 million or 38.8% of adjusted revenue, an increase of $48 million or 9.4% from Q1 '23, the 38.8% and EBITDA margin reflects a year-over-year improvement of 150 basis points. The 150 basis point margin expansion reflects the positive impact of both revenue growth and disciplined expense management.
Net interest expense for the first quarter of '24 was $116 million, an increase of $4 million from Q1 '23. The average interest rate in the quarter for the amended credit facility, including the senior notes, was 6.86% compared to 6.21% in the first quarter of '23.
Adjusted net income, as defined in Note 4 in the earnings release was $324 million the adjusted diluted EPS was $1.28. The effective tax rate used for adjusted net income was 26%. Despite the quarterly share repurchase activity, a higher average stock price drove the diluted share count up to 253.3 million from 252.1 million for Q4 '23.
SS&C ended the first quarter with $413 million in cash and cash equivalents and $6.7 billion in gross debt. SS&C's net debt, as defined in our credit agreement, which excludes cash and cash equivalents of $95 million held at DomaniRx was $6.4 billion as of March 31. Our last 12-month consolidated EBITDA used for covenant compliance was $2.156 billion as of March 2024.
Based on net debt of approximately $6.4 billion, our total leverage ratio was 2.95x, down from 3.05x at year-end. Our secured leverage ratio was 2.02x as of March 31. The $3.5 billion of our term loan B matures in April 2025, and we are currently evaluating our debt financing options, looking to go to market in the near future.
As we look forward to the second quarter and the remainder of the year with respect to guidance, note that we will remain focused on client service and assume that retention rates will be in the range of our most recent results.
We will continue to manage our expenses with a cost disciplined approach by controlling and aligning variable expenses to ensure efficiency, increasing productivity to improve our operating margins to leverage our scale and effectively investing in the business through marketing, sales and R&D to take advantage of the future growth opportunities ahead of us.
Specifically, we have assumed foreign currency exchange will be at current levels, interest rates to remain at current levels with the potential of a couple of short-term rate declines in late 2024 and our refinancing will not materially impact our interest rate expense but is obviously subject to varying market conditions.
GAAP tax rate of approximately 26% on an adjusted basis, which is unchanged from prior guidance. Capital expenditures to remain at the 4.3% to 4.7% of revenues, which is unchanged from prior guidance and a similar historical weighting share repurchases and debt reduction.
For the second quarter of '24, we expect revenue to be in the range of $1.412 billion to $1.452 billion, adjusted net income in the range of $295 million to $311 million; interest expense, excluding amortization of deferred financing costs and original issue discount in the range of $112 million to $114 million; diluted shares in the range of $253 million to $254 million, and adjusted diluted EPS in the range of $1.16 to $1.22.
For the full year 2024, we are raising revenue guidance by $7 million, and we expect revenue to be in the range of $5.695 billion to $5.855 billion, adjusted net income in the range of $1.242 billion to $1.322 billion, diluted shares in the range of $252 million to $255 million, adjusted diluted EPS in the range of $4.93 to $5.17 and cash from operating activities to be in the range of $1.302 billion to $1.382 billion.
Our updated 2024 guidance reflects our strong results in the first quarter with a continued positive outlook for the remainder of the year. That also reflects our cost disciplined approach and expected margin expansion over the course of the year.
Now I'd like to turn it back over to Bill for final comments.