Gregory H. Jaske

Greg maintains a broad-based real estate practice that includes negotiating and structuring LLC and other joint ventures, acquisitions, purchase and sale agreements, development agreements, ground leasing and borrower-side financings.

With extensive experience in New York City and nationwide, Greg has guided clients through multimillion dollar joint venture agreements, representing both operators and investors in significant multifamily, commercial, and mixed-use properties and development projects. He also regularly counsels clients in telecommunications real estate matters, including data center development and leasing and rooftop facility leases, as well as tenant-side retail healthcare leasing. In addition, Greg has substantial experience in commercial real estate financing matters, from loans to purchases of co-lending interests and loan participations totaling billions of dollars in loan originations.

Greg frequently serves as lead counsel in high-stakes real estate matters, including representing a multi-billion-dollar family office in its negotiation of real estate joint ventures with sponsors for horizontal and vertical phases of development. Clients rely on him for his ability to structure and negotiate joint venture agreements, purchase and sale agreements, development agreements, property and asset management agreements, office and retail leases, telecom-related real estate agreements and real estate-related corporate matters.

Prior to joining Olshan, Greg worked at Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. and other prominent New York law firms, where he handled a wide array of real estate matters, including complex joint ventures and development projects. He began his career as an analyst at a leading international financial services institution and a hedge fund.

Greg grew up and resides on Long Island. He enjoys spending family time skiing, hiking and exploring the Catskills.

Unique Transactions

• Represented the fee owner in a leasehold restructuring of a data center facility, consisting of the simultaneous negotiation of (a) the surrender of the ground lease of the facility pursuant to an option contract, (b) the negotiation of an amendment to the existing space tenant (a major international financial institution), and (c) the negotiation of a new lease with a new space tenant (another major international financial institution) for the unoccupied portion of the facility.
• Represented a multi-billion-dollar family real estate business in creating a Manhattan development site through a joint venture agreement for one of the tenant entities in a multi-tiered ground lease covering several adjacent parcels of land and excess development rights for the development of a 400,000+ square foot office building.

Joint Ventures

• Represented a multi-billion-dollar family office in its negotiation of real estate joint ventures with various real estate sponsors for the horizontal and vertical phases of:
  • A new 1,000,000 square foot logistics facility in California;
  • A 500,000 square foot apartment complex redevelopment in Florida;
  • A 400,000 square foot office complex repositioning in North Carolina;
  • A 400,000 square foot office to residential conversion project in Texas;
  • A 250 unit garden complex repositioning in Texas;
  • A 125,000 square foot industrial facility in California;
  • A new 400 pad recreational vehicle park in Texas;
  • A 100,000 square foot retail facility redevelopment in Connecticut; and
  • A new 100,000 square foot office complex in northern California.
• Represented a multi-billion-dollar family real estate business in connection with joint venture agreements for the ground up development of 3 multifamily buildings in Jersey City containing 500 units in the aggregate.

• Representation of a real estate company, as sponsor, in the negotiation of a programmatic joint venture with an institutional capital partner for the deployment of $166 million of equity toward the purchase of value add light industrial assets in the northeast. Negotiated a follow-on joint venture between the same parties for the deployment of an additional $250 million of equity in a broader geographical area.

• Represented one of the largest real estate investment firms in the world in connection with a programmatic joint venture with two sponsors for the deployment of $100 million of equity for the acquisition of medical office buildings.

News

Honors & Recognitions

• Recognized in The Best Lawyers in America® as “One to Watch” for Real Estate Law, 2025
• Named a “Rising Star” by New York Metro Super Lawyers annually since 2017

Professional

• Member of the Board of Trustees at Friends Academy, a private Quaker K-12 college preparatory school in Locust Valley, New York