Brian J. McDade
Executive Vice President and Chief Financial Officer at Simon Property Group
Thank you, David. Real-estate FFO was $3.35 per share in the first -- in the fourth quarter compared to $3.23 in the prior year, 3.7% growth. Domestic and international operations had a very good quarter and contributed $0.18 of growth.
During the quarter, we sold assets that resulted in a tax benefit, which partially offset the prior tax expense from our ABG sale and essentially offset a write-off of pre-development costs associated with a joint-venture development project in California. Leasing momentum continued across the portfolio. We signed more than 1,500 leases for 6.1 million square feet-in the quarter.
For the year, we signed a record 5,500 leases for more than 21 million square feet. Approximately 25% of our leasing activity for the year were new deals. Malls and outlet occupancy at the end-of-the fourth quarter was 96.5%, an increase of 70 basis-points compared to the prior year.
Our year-end occupancy is the highest-level over the last eight years. The mills occupancy was 98.8%, an increase of 1% and is at a record level. Average base minimum rent for the malls and outlets increased 2.5% year-over-year and the mills increased 4.3%. Retailer sales per square-foot was $739 for the year.
Strong revenue growth across our businesses, combined with expense discipline resulted in a 100 basis-point increase year-over-year in our industry-leading operating margin. Our occupancy cost at the end-of-the year was 13%. Domestic NOI increased 4.4% year-over-year for the quarter and 4.7% for the year. Portfolio NOI, which includes our international properties at a constant-currency, grew 4.5% for the quarter and 4.6% for the year.
Fourth quarter funds from operation were $1.39 billion or $3.68 per share compared to $1.38 billion or $3.69 per share last year. fourth quarter results include $0.20 per share of non-cash after-tax gain from the combination of JCPenney and Spark Group. The mark-to-market fair-value of exchangeable bonds increased year-over-year, which offset a lower contribution from OPI operations. As a reminder, the prior year results include $0.33 per share in gain from the sale of part of our interest in ABG last year.
Turning to new development and redevelopment. This year, we will open our first premium outlets in Jakarta, Indonesia in March and expect to begin construction on four to five mixed-use projects throughout the year. We expect to fund these redevelopments and mixed-use projects with our internally generated cash-flow of over $1.5 billion after our dividend payments. Other platform investments, JCPenney and Spark Group combined to form a portfolio of iconic retailer banners called Catalyst brands.
Catalyst brings together SPARC brands, Aeropostale, Brooks Brothers, Eddie Bauer, Lucky and Nautica with J.C. Penney in its exclusive private brands. Catalyst sold Reebok in early-January and is currently evaluating strategic options for Forever 21. We view the Catalyst transaction as a positive development that will create significant synergies with a solid balance sheet that will enable the company to drive EBITDA growth. Catalyst shareholders include Simon, Brookfield, Authentic Brands Groups and Sheen.
Turning to the balance sheet. During '24 -- during 2024, we completed $11 billion in financing activities, including issuing $1 billion in senior notes with a 10-year term and a 4.75% interest-rate. We recasted our $3.5 billion revolving credit facility with maturity extended to January of 2030 and no change in pricing or terms and completed over $6 billion of secured loan refinancings and extensions.
Lastly, we delevered our balance sheet by approximately $1.5 billion in the year and ended the year at 5.2 times net-debt to EBITDA. Our A-rated balance sheet provides a distinct advantage with more than $10 billion of liquidity at year-end. Additionally, today, relative to our dividend, we announced a dividend of $2.10 per share for the first-quarter, a year-over-year increase of 7.7%. The dividend is payable on March 31.
Now moving on to our 2025 guidance. Our real-estate FFO and our real-estate FFO guidance range is $12.40 to $12.65 per share. Our guidance reflects the following assumptions, domestic property NOI growth of at least 3%; increased net interest expense compared to 2024 of between $0.25 to $0.30 per share, reflecting current market interest rates and projected cash balances compared to 2024.
Lastly, our diluted share count of approximately 377 million shares and units outstanding, due to the recent Catalyst brands transaction, we will not include catalyst guidance at this time. We expect there will be significant savings and synergies from the combination that will be coupled with potential restructuring costs. We expect Catalyst will generate positive EBITDA in fiscal 2025 and roughly breakeven FFO as they work-through the combination.
Oh. With that, thank you. And David and I are now available for your questions.