Overall, we remain comfortable with our reserves and continue to hold buffers as we maintain a prudent and conservative approach to our reserving. Our investment results have again been strong this quarter, and we are ahead of our full year guidance on a run rate basis. As a result, we are increasing the 2023 full year net investment income guidance to $250 million to $260 million, up from $220 million to $240 million. Our investment strategy remains focused on high-quality fixed income instruments with an average credit rating at AA, and we remain well placed to manage market volatility. Our portfolio is performing well, and we saw no defaults across the portfolio during the first 9 months of this year. Moving on to our MGA strategy, which is core to our business.
This year, we launched the SiriusPoint International MGA Center of Excellence to deliver an efficient and collaborative onboarding experience for new MGA partners in our London international business. The program mirrors our North American structure and improves both quality of experience and operational efficiency by allowing our partners to access expertise across SiriusPoint’s global platform. Our partner pipeline is strong in both international and North America, and we are being selective. We want to work with partners who share our disciplined approach to underwriting and operate in a data-centric way. Equally important is the cultural fit. We want to work with like many partners who share our philosophy. Since the second quarter, we have onboarded three new MGA partnerships, which are pure underwrite relationships and involve no equity stakes in line with our disclosed strategy.
Overall, MGA results remain strong. Capital light fee income from our five consolidated MGAs is growing strongly year-on-year with revenues up 7% versus the previous year, while service margin is up 1 percentage point to 21%. The book value of the five consolidated MGAs is only $92 million, but we believe the actual economic value is significantly higher given their attractive growth profile and earnings generation capability and are not fully reflected in SiriusPoint’s share price, a point I will continue to make. We have made progress on reducing the number of equity stakes in MGAs to concentrate on fewer and deeper MGA relationships and have now sold seven states since the start of the year. Banyan, which is one of our consolidated MGAs and one more stake was sold during Q4 bringing our total holdings down to 29 equity stakes from 36 at the year-end.
Banyan results were consolidated in our 9-month financials. However, we will stop consolidating them effective fourth quarter ‘23, but will continue to provide underwriting capacity to them. Overall, all three areas of our business are delivering strong results compared to prior years and we are continuously improving performance. Moving on to our balance sheet, which is strong. Book value was stable this quarter on an ex-AOCI basis has increased by 3% during the quarter and 14% since year-end ‘22. Our capital position is stronger with our BSCR ratio at 238% at the end of the second quarter versus 219% at the first quarter ‘23. Our debt leverage remained stable at 25.3%. We are exploring ways to optimize our capital structure. Let me end where I started.
We have made significant progress in the past 12 months for our shareholders. But 2023 is not a destination, it is a platform for further improvement, and our game is to make 2024 a step-up again. Whilst we continue to shape the portfolio with some top line impact, our ultimate ambition is to make this a growing and profitable company that operates at best-in-class levels. Rest assured, we are working incredibly hard to achieve that with no complacency. We know the journey from underperformer will not be a straight line, and we will make some mistakes. But all that said, 2023 has been an important year in reestablishing the inherent potential of SiriusPoint. I’d like to thank all our stakeholders, shareholders, customers and employees for their support and patience while we execute our actions.
We believe the future is brighter as a consequence of the. With these remarks, I’ll now pass over to Steve who will take you through the financials.
