Let me now walk you through the financial results for Q1 fiscal year 2025. Page 3, please. Highlights. The upper part of the page shows the results for Q1 fiscal year 2025. Orders received reached JPY 424.3 billion, driven by strong demand in the businesses including carbon solutions and Civil Aero Engine, representing significant growth from the previous fiscal year. However, both revenue and profits declined from the previous fiscal year due to the absence of last year's large projects and the impact of the yen appreciation, although the Civil Aero Engine business expanded steadily. Revenue was JPY 337.7 billion, operating profit JPY 20.8 billion, and profit attributable to owners of parent JPY 11.6 billion. Cash flow from operating activities decreased from the previous fiscal year, mainly due to increased tax payments. The lower half of the page shows the forecast of fiscal year 2025.
We have maintained the forecast we presented in May due to many uncertainties around U.S. tariffs and the increasing uncertainty in the global economy. Next, page 5, please. Overview of financial results. You will find the numbers for orders received, revenue, profit attributable to owners of parent, and cash flows from operating activities, which I already touched upon earlier. The lower part of the table shows the exchange rate. As you find, yen has appreciated compared to the same period last year, which had a significant negative impact on the profit attributable to owners of parent. However, there is almost no impact on the cash flow since this is mostly due to foreign exchange translation. Next, page 6, please. Financial results by segment. Starting from orders received, we secured large projects in the carbon solutions business, driven by increasing demand for energy transition.
Civil Aero Engine and defense businesses also expanded steadily. Revenue and operating profit in the Resources, Energy, and Environment segment and the Social Infrastructure segment declined, mainly due to the absence of large projects from the previous year. Meanwhile, the Aero Engine, space, and defense segment, a growth business, achieved year-on-year increases in both revenue and profit. Next, page 7, please. This page onward explains the overview of each segment. Page 7 covers the Resources, Energy, and Environment segment. Revenue declined year-on-year in the carbon solutions business due to the absence of last year's large projects and deteriorating performance at overseas subsidiaries. Nuclear energy and Asian-based EPC also saw a profit decline due to the previous year's better performance. Operating profit temporarily declined due to upfront cost recognition in domestic nuclear energy projects. However, we expect profits to improve from Q2 onward. At our U.S.
subsidiaries under the carbon solutions business, which faced weaker performance last year, we have initiated structural reforms from Q1, focusing on higher margin projects and implementing workforce reduction to cut fixed costs. Next, page 8. Social infrastructure. In Q1, revenue and profit declined due to the absence of large projects from the previous year. As announced the other day, we plan to merge IHI Infrastructure System and IHI Infrastructure Construction on November 1st, 2024. The purpose of this merger is to focus on the domestic bridge maintenance business, which is expected to grow over the medium to long term, while leveraging synergies within IHI Group. In addition, we resolved today to transfer our Transportation Systems business to J-W Partners Group . Page 9, industrial system and general purpose machinery. Revenue slightly declined, mainly due to the absence of projects from the previous year.
Operating profit remained roughly the same as last year. Although transport machinery revenue declined, profitability improved in the vehicular turbocharger business, thanks to better sales pricing and fixed cost reductions. The impact of tariffs on vehicular turbochargers in Q1 was minimal. We have reached agreements with some customers to share the tariff impact burden, but we remain cautious in assessing the overall impact on the full year.
Next, let's take a look at Aero Engine Space and Defense. Revenue continues to grow solidly year-on-year. Driven by the defense business and the Civil Aero Engine business, operating profit also increased year-on-year. We saw a significant expansion in sales of spare parts for V2500 and other models, driving solid continuous growth. Although in the first quarter we experienced minimal impact of the tariff, full-year impact still remains an uncertainty, and we are continuing to assess the situation to ascertain the overall impact. To mitigate the impact, we are working with our program partners on initiatives such as partially shipping new engine parts directly to overseas assembly plants instead of shipping them via the U.S. We are also continuing our internal efforts to further reduce costs. The graph on page 11 should look very familiar to you.
You can see that the Civil Aero Engine business in GAAP basis is continuing to grow quite solidly. Next, page 12 shows the trend on spare parts handling amount in non-GAAP basis. In the first quarter, spare parts sales continued to grow solidly, increasing by more than 20% from the same period last year. Next page, the Consolidated Balance Sheet. The equity ratio and D/E ratio have improved from the end of the previous fiscal year. We will continue to rigorously manage our balance sheet to further strengthen our financial position. Page 14 is on cash flow. In the first quarter, operating cash flow decreased to JPY 5.3 billion due to a year-on-year decline in revenue, as well as the incremental tax expenses, despite significant improvements in working capital across the group, which is a contribution of our initiatives to compress the working capital.
Investment cash flow also increased year-on-year as we are ramping up investments for growth. As a result, we saw free cash flow decline year-on-year to JPY 20.9 billion. Now, I'd like to move on to the Consolidated Full-Year Outlook. We have decided not to revise our full-year guidance at this point of time, taking into account the uncertainties around the impact of U.S. tariffs and other factors on the global economy. Continuing on to page 17. Although we have not revised the Consolidated Full-Year Guidance, we did make adjustments to shift the numbers across the segments. The business transfer gains of JPY 15 billion previously included in the Other segment is now shifted to be included in the Industrial Systems and General Purpose Machinery segment. This primarily reflects the net gain from three business transfers completed in the period between April and July. Next, let us turn to page 18.
We have made a resolution today to implement a stock split. We are implementing a 1:7 split with the record date of September 30th and effective date of October 1st. The revision of the dividend forecast at the bottom of the page is nominal and does not represent any substantial change to the actual dividend payout. Finally, please take a look at page 20. Allow me to make an update on the progress of the reformation of our business structure. We have made release on three new additional initiatives highlighted by the red box since the main announcement. In June, we have decided to transfer a portion of the shares of Japan Marine United Co., Ltd. and today, we have made a resolution to transfer the shares of Niigata Transys Co., Ltd. and Macy Electric Co., Ltd.
We will continue to execute the reformation of our business structure and ensure further improvement in profitability and efficiency, eyeing on significant growth starting from the next fiscal year and beyond. I'd like to stop here on my presentation. Thank you very much for your kind attention.