Donald E. Sonnenborn

Donald Sonnenborn is co-chair of the firm’s Real Estate Practice Group. He advises major U.S. developers as well as landlords and lessees on office, commercial and retail properties, from acquisition, finance, management and leasing through disposition.

With clients that include some of the largest commercial landlords, property owners, best-known developers, national and international retailers, and financial services companies, Donald excels at negotiating large-scale leases for both landlords and tenants, helping his clients secure properties, manage risks and restructure troubled leases. He has handled many of New York City’s biggest leasing deals involving iconic office buildings and complexes such as Rockefeller Center, the MetLife Building, the Chrysler Center and many others. In addition, he has handled the lease-ups of major new developments including Hudson Yards and Jackson Park.

Donald is well versed in the unique issues involved in leasing to international tenants and those with sovereign immunity, and experienced in resolving the financial and corporate real estate collateral issues that arise in commercial and retail acquisitions and dispositions. Major developers also turn to him to represent them in forming joint ventures for the acquisition and development of real estate.

Practical and realistic in his approach, Donald applies his deep market knowledge, attention to detail, negotiating acumen, and common sense to ensure his clients have the information they need to close the best deals. From initial discussions through preparing and reviewing final legal documents, Donald helps his clients realize their objectives.