Mike Mathias
Analyst · Barclays
Thanks, Jay. Good afternoon, everyone. I'm pleased to report that the fourth quarter and year were far better than expected at the onset of the pandemic. We saw sequential improvement in each quarter, ending on a positive note with fourth quarter adjusted operating income up 38% to last year, driven by strong merchandise margins across brand and channels. Our performance really speaks to the quick action, vision and strong execution of our teams. In the fourth quarter, total company revenue declined 2%, with strong online sales, mostly offsetting declines in stores.
Digital revenue rose 35%, with Aerie up 75% and AE, up 20%. Online sales for the quarter and the year represented approximately 45% of our total mix increasing significantly from 29% for the full year 2019. Digital KPIs were very strong with double-digit traffic growth, improved conversion and a high single-digit increase in AUR. Our focus on tightening assortment breadth and optimizing inventory levels enabled us to control promotions and drive greater full price sell-through.
Store channel revenue decreased 20%, reflecting mall traffic declines. As anticipated, store revenue declined across both brands as we lapped high volumes, seasonal store events like Black Friday and Super Saturday, which were meaningfully impacted by the pandemic. We also dealt with the impact of store closures across Canada, California and other regions that reduced total selling days by 6% relative to last year's fourth quarter. Continuing to trend throughout the year, these pressures were partly offset by strong conversion in AUR.
By brand, Aerie continues to demonstrate strong momentum. Revenue increased 25% to $337 million in the fourth quarter. Comparable sales grew 29%, building on a 26% increase last year. With AE's greater store penetration, the brand was more affected by the store channel headwinds. However, we were pleased to see improvement in the third quarter. Brand revenue declined 9% to $943 million. AE comparable sales declined 8%.
Total AEO gross profit dollars increased $32 million or 8% during the quarter, and gross margin expanded 300 basis points to 34%. Merchandise margins expanded significantly, reflecting the benefit from continued promotional discipline and our inventory optimization initiatives. Our product assortments were well received, which enabled higher full price selling.
As Jay mentioned, rent leveraged as a result of negotiated savings and benefits from recent impairments. Offsetting this, we saw higher delivery, distribution and warehousing costs as well as higher incentive compensation. Yet, the impact of delivery cost pressure was less significant than expected, reflecting strong execution and efficiency benefits from new fulfillment capabilities.
SG&A expense increased 2% due to higher incentive compensation. This was better than our expectation due to our ongoing focus on expense management across labor and other store-related costs. In the absence of incentive compensation, SG&A would have declined 4%. Adjusted operating income of $106 million increased 38% compared to last year. Adjusted operating margin of 8.2% expanded 240 basis points. Adjusted EPS was $0.39 per share in the quarter. Our diluted share count was 197 million and included 26 million shares of unrealized dilution associated with our convertible notes.
Now some detail on our brands. I'm really pleased to see both brands generate strong increases in operating income, which is a testament to our ROI mindset and strategic execution. American Eagle adjusted operating income increased 29% to $145 million despite the revenue decline. Adjusted brand operating margin improved 450 basis points to 15.4% due to merchandise margin expansion and rent savings.
While we have made incredible progress at American Eagle, I want to underscore that there is still meaningful opportunity for future profit improvement. Aerie adjusted operating income grew 52% to $48 million. Adjusted brand operating margin expanded 250 basis points to 14.3%, reflecting merchandise margin improvement and expense leverage from revenue growth. Corporate unallocated expense increased 28% to $87 million, primarily due to incentive compensation.
Ending inventory was down 9%. American Eagle inventory declined 21% due to continued inventory optimization initiatives as well as lower end-of-season clearance. Aerie's inventory increased 10% to support demand growth. The clearance was lower to last year. We are very pleased with our inventory discipline during 2020, which is validated by a long-held view that we can meet customer demand and deliver an exceptional experience while generating higher returns on inventory investments. This work is ongoing, and I believe will have a material impact on our profit improvement over the next several years.
Our balance sheet was an advantage during 2020 and continues to strengthen. During the fourth quarter, we generated $213 million in operating cash flow and ended the period with $850 million in cash and short-term investments. At year-end, our total available liquidity, including our undrawn revolver, was approximately $1.2 billion. Our only debt currently outstanding is our convertible note.
As Jay mentioned, we are pleased to reinstate our dividend and have also unsuspended our share repurchase program. In 2021, we expect capital expenditures of $250 million to $275 million, which is up from $128 million in 2020 and in line with the average annual target we shared at our investor meeting.
We will continue to actively monitor our store fleet. We closed 57 total locations in 2020, including over 50 American Eagle stores. The sales and customer transfer rates from these locations will inform our decision-making around our 2021 lease expirations. The vast majority of our 2020 store renewals were for 1 year, so we have significant flexibility, including almost 450 leases expiring this year. We expect to continue to negotiate material rent savings and plan to open approximately 60 area locations, including 25 to 30 OFFLINE stores, which will be a mix of stand-alones and Aerie side-by-side.
At our Investor Day in January, we laid out a path to $5.5 billion in revenue and a 10% operating margin by 2023. Our back half results increase our confidence in these goals, and we expect to make continued progress in the coming year.
Looking ahead, we are pleased with how we started the year and expect our 2021 results to put us on a strong path to our 2023 targets. Yet, the operating environment remains uncertain, so we are not providing annual guidance at this time. Regarding the first quarter, we expect revenue and operating income to exceed our results from the first quarter of both 2020 and 2019.
In closing, we began implementing our go-forward strategies to drive Aerie's growth, optimize AE's profitability, establish leading capabilities and continue to focus on investment returns. Our strong performance during the fourth quarter is a key proof point that validates our approach and strengthens our confidence in our future opportunity.
With that, we will open it up for questions.