Christopher T. Forsythe
Senior Vice President and Chief Financial Officer at Atmos Energy
Thank you, Kevin, and good morning, everyone. As Kevin mentioned, our fiscal '25 first-quarter diluted earnings per share was $2.23, which represents a 7.2% increase over the prior year quarter. Consolidated operating income increased 15% to $459 million in the first-quarter. This performance was driven by several factors. Rate increases in both of our operating segments totaled $69 million. Residential commercial customer growth, combined with higher industrial loads increased operating income by an additional $10 million. Finally, APT's through system revenues increased by $8 million, driven by both an increase in throughput and spreads.
These market conditions were largely driven by capacity constraints experienced primarily in the first-half of the first-quarter due to maintenance and some unplanned outages on various pipelines. Since that time, spreads have returned to more normal historical norms for this time of the year. Partially offsetting these increases was a $41 million increase in consolidated O&M, driven by several factors. Bad expense increased $15 million. As a reminder, we recognized a $14 million non-recurring reduction in bad debt expense in the prior year quarter, resulting from a regulatory change in how we recover our bad debt expense in the Pacific.
Employee-related costs increased approximately $11 million, primarily due to increased headcount to support company growth and higher -- higher overtime and standby costs driven by increased service work. We also experienced an $8 million increase in compliance and spending associated with increased leak survey work within our distribution segment and timing of the in-line inspection work-in our pipeline storage and other segments. Finally, we experienced a $5 million increase in APT's system safety and integrity expense, which is offset by a corresponding increase in revenue as a result of APT's new system safety and integrity mechanisms. Therefore, this increase had no impact to operating income.
We are off to a good start from a regulatory perspective. Since the beginning of the fiscal year, we have implemented $152 million in annualized operating income increases in our distribution segment. Of this amount, $117 million relates to the implementation of our two annual rate revenue mechanisms in Texas and $28 million relates to the implementation of our two annual filings in the Pacific. Currently, we have seven filings in-progress seeking approximately $126 million in annualized operating income increases. Included in this filed for amount is approximately $90 million in Texas from four filings. The first is a $40 million system-wide general rate case in our West Texas distribution that we filed last fall. As a reminder, this is a required filing that affects all of our customers in West Texas-based on the settlement we reached in 2020. Additionally, we required refresher rates following five years of grit volumes for portions of our West Texas division.
During the first fiscal quarter, we filed two new cases in our mid-tech division seeking $20 million as the five-year grit filing cycle had ended for these jurisdictions. And in January we filed our annual filing mechanism with the City of Dallas, seeking a $30 million increase in annualized operating income. Finally, we have a general rate case in-progress in Kentucky seeking approximately $34 million. These filings are proceeding as planned and we anticipate completing all of them by late-spring of 2025. We plan to make additional filings this fiscal year seeking approximately $300 million in annualized operating income increase.
During the quarter, we completed over $1 billion of long-term debt and equity financing, highlighted by the $650 million long-term debt financing we completed in October 2024. Additionally, we settled $380 million in equity forward agreements. Our equity capitalization as of December 31 was 60% and we did not have any short-term debt outstanding. We upset $5.2 billion in available liquidity. This includes approximately $1.5 billion of net proceeds available under existing forward sale agreements, which is expected to satisfy the remainder of our anticipated fiscal '25 equity needs and almost all of our anticipated equity needs for fiscal '26. Our first-quarter results have positioned us well to achieve fiscal 2025 earnings per share in the range of $7.05 to $7.25. And we would remain on-track to achieve our capital spending plan of $3.7 billion.
Thank you for your time this morning. I will now open up the call for questions.