Blackstone Weighs Sale of Willis Tower

Key Points

• Blackstone is quietly testing investor interest in Willis Tower
• Any buyer would need to assume the $1.3B mortgage, not refinance
• Strong leasing and Skydeck revenue are being offset by higher rates and taxes

Blackstone may be preparing to test the market on one of the most recognizable office assets in the country. The firm is reportedly exploring a potential sale of Willis Tower, the 110-story Chicago skyscraper it has owned for roughly a decade. Instead of launching a full marketing process, Blackstone has approached a small group of investors willing to step into the building’s $1.3 billion securitized loan. That structure reflects today’s reality for large office trades, where assuming existing debt is often the cleanest path to liquidity. Eastdil Secured is said to be running those conversations. This is not distress. It is a calculated look at capital efficiency.

A High-Cost, High-Profile Repositioning

Blackstone acquired Willis Tower in 2015 for $1.3 billion, assuming debt as part of the transaction. Since then, the firm has invested roughly $670 million into repositioning the property. The overhaul modernized the office component, introduced the 300,000 square foot Catalog retail and entertainment complex, and expanded the Skydeck, which has become one of the city’s most reliable tourism revenue engines. Those investments paid off operationally. As of late 2025, the building was 84 percent leased, supported by tenants such as Adtalem Global Education and Zurich North America. The Skydeck now attracts more than 1.2 million visitors annually, with revenue up 15 percent year over year. By most operating metrics, the asset is performing.

Valuation Depends on One Big Question

Despite the leasing momentum, Willis Tower’s value remains difficult to pin down. Appraisals over the past year have ranged from roughly $999 million to $1.4 billion, with much of the variance tied to how underwriters treat Skydeck income. Some view it as a durable, recurring cash flow. Others discount it as non-core to office valuation. That spread matters when the loan balance sits at $1.3 billion, and equity margins are thin.

Debt Pressure Is Driving the Timing

The tower’s floating-rate loan is current and cash flowing. Blackstone even secured flexibility last year by extending the maturity to March 2028, with two one-year extension options. Still, rising rates are compressing returns. Annual debt service climbed to $91.4 million in 2024, up sharply from $66.4 million in 2018. Real estate taxes have also surged well beyond original underwriting assumptions. While net operating income continues to cover debt service, the debt-service coverage ratio has steadily deteriorated, a trend institutional owners cannot ignore.

Why This Matters for Office Investors

Willis Tower is a case study in today’s office market reality. Even fully repositioned, best-in-class assets are vulnerable to capital stack pressure when floating rate debt resets higher, and expenses outrun projections. If Blackstone chooses to exit, it will underscore a broader theme. Office values are increasingly set by debt structure, not just leasing performance.

Bottom Line

Willis Tower remains one of the strongest performing office assets in the country from an operational standpoint. But higher interest costs and taxes are tightening the hold window, even for global trophy assets. Blackstone’s quiet outreach suggests that in 2026, discipline around leverage and liquidity is driving decisions at the very top of the market.