Thank you for joining OCI Holdings Company's First Quarter 2025 Earning Call. I am Su Mi Lee, COO of OCI Holdings Company. I will briefly walk you through the presentation materials uploaded on our website. First, let me explain consolidated operating result on page five. In Q1, we recorded a sales revenue of KRW 947 billion and operating income of KRW 49 billion, with an operating margin of around 5%. Our operating income, which was a loss in Q4, turned positive QoQ. The polysilicon business has maintained normal operation after scheduled maintenance, and there was a slight improvement in sales volume. In addition, the urban development business returned to normal operation after eliminating a large-scale accounting loss in the previous quarter. Thankfully, most of our major subsidiaries, except the chemical business, showed improved operating result despite the market downturn.
Let me provide details on the performance of key subsidiaries in the following pages. Please refer to the consolidated financial position as of the end of the first quarter on page seven. Compared to the end of last year, total assets and liabilities slightly decreased. On the assets, accounts receivables declined following the collection of final installments from unit owners after move-ins were completed in this area. OCI Company's acquisition of 100% of P&O Chemical and its consolidation into our balance sheet resulted in an increase in PP&E. On the liabilities, the land sold for its business of this area has accounted to in advance payment. This area repaid part of its short-term borrowings using cash collected from receivables and its land sale, which contributed to lowering net debts. Our leverage ratio still remains strong at 67%. Next, let me go over the performance of key subsidiaries.
Page eight covers the performance of OCI TerraSus, our polysilicon business. In Q1, OCI TerraSus sales revenue increased by 19%, and operating income turned positive. In addition to sales under long-term agreements, we secured additional volume from tariff-low-risk countries during the first quarter. Manufacturing costs normalized after maintenance, and we operated at approximately 90% capacity. However, demand from U.S. export-based customers was lower than expected due to tariff uncertainties. As reflected in the 2024 earnings of solar companies, our peers and customers are experiencing significant losses and maintaining low utilization rate. Consequently, we plan to temporarily adjust our operation rate to manage inventory and secure working capital. Anyhow, as we are seeing many opportunities and receiving positive signals from discussions with new customers, we believe this adjustment is temporary, and we are targeting recovery in the second half of the year. Page nine highlights the performance of OCI Enterprises.
Our U.S. business saw a 110% increase in sales and returned to positive operating income, driven by revenue recognition from solar project sales. Additionally, module sales volume exceeded our plan, contributing further to sales revenue. However, as we prepare for cell production, we temporarily closed the module production line in March, and related line disposal has been reflected in Mission Solar Energy earnings. For Q2, we plan to sell off the remaining module inventory and proceed with our cell investment, aiming to begin production in the first quarter next year. OCI Energy is targeting the sale of additional solar projects totaling 220 MW by the end of the second quarter, which will support OCI Enterprises' earnings. Page 10 outlines the performance of OCI SE's cogeneration power plant. OCI SE recorded 10% revenue growth and a 7% increase in operating income.
While the SMP, our main sales and profit driver, remained flat QoQ, higher REC sales volume with its price contributed to revenue growth. However, margin declined due to higher raw materials cost and adverse currency effects. Looking ahead to the second quarter, we expect SMP to remain low due to reduced electricity demand, and costs will rise due to scheduled maintenance. We aim to enhance operating efficiency and expand steam sales in the mid to the long term. Page 11 presents the performance of DCRE, our urban development project. DCRE's operating income turned positive QoQ, mainly due to the low base effect following a large accounting loss in the fourth quarter. As the sales revenue declined slightly with the completion of Complex 3 and 4, current sales revenue and profit recognition are based on the progress of Complex 6.
In the second quarter, we began the pre-sale of Complex 7, consisting of 1,734 units. Once sales are completed, revenue and profit will be recognized according to the construction progress. Although the housing market is still in recovery amid ongoing uncertainty, we are making steady progress. We aim to complete urban development by 2029. Next is regarding OCI Company's performance on page 11. For detailed explanations, please refer to OCI Company's IR materials. OCI's operating income declined by half QoQ. A prolonged economic downturn and inflation has delayed demand recovery for chemical products and narrowed margin spreads. Although we cannot provide an aggressive short-term outlook, we will continue to focus on operational efficiency with margin protection, and we will try to expand to the more value-added business. Let me move on page 13, key management updates. Last month, OCI Enterprises announced its cell investment, which we publicly disclosed.
OCI Holdings Company will continue to expand our solar business with a strategy to build a U.S. solar value chain that links OCI TerraSus non-China polysilicon to the U.S.-made cell and modules. We aim to start commercial production in Q1 next year, and the preparations are progressing well. As many of you know, U.S. cell capacity significantly lags behind module capacity, and strong demand is expected for DCA-compliant cells. Please refer to the bottom of the page for the investment details. Finally, I will show the solar business environment and our plans on page 14. This quarter was marked by increased market uncertainty due to trade policy changes from the Trump administration. We operated at near-full capacity while waiting to assess the pace of demand recovery, but clear signals have yet to emerge, leading to an inventory buildup at OCI TerraSus.
Accordingly, we will reduce our polysilicon operating rates in Q2 to manage inventory level and working capital. However, we believe the market has bottomed out and are seeing growing opportunities in the U.S. solar industry. Anti-dumping and countervailing duty rates for four Southeast Asian countries were just released this week. It will take time for the solar value chain to adjust to the new tariff structure. In the short term, we'll facilitate inventory sales under our LTAs and pursue new orders from customers in low-risk tariff regions. We are also engaging directly with emerging capacities in Africa, the Middle East, and India. We target the second half of the year for business turnaround. In the meantime, we plan to secure sales contracts with U.S.-based customers and continue to explore downstream opportunities and strategic partnerships.
Year 2025 will be very challenging for all entrepreneurs, though, as we see both the risks and opportunities, we will try to grow and survive and progress in this turmoil. If you have any questions, please contact our IR team. Thank you for your interest in OCI Holdings Company.