Key Takeaways SLG signed a 64,077-sq-ft lease with Sigma Computing at One Madison Avenue. The new lease brings the property's total leased space to 78.1% amid strong 2025 leasing momentum. SLG has secured 1,260,707 sq ft in Manhattan office leases year to date, with a 1M sq ft pipeline.SL Green Realty Corp. (SLG) recently announced the signing of a new lease with Sigma Computing, Inc. for 64,077 square feet on a portion of the 3rd floor at One Madison Avenue, resulting in the property being 78.1% leased.S ...