Meet the leaders of GreenStreet

Peter Marino

Chief Executive Officer

Peter is a seasoned professional with over 40 years of industry experience, establishing a national reputation built upon unwavering integrity, loyalty, and a steadfast commitment to client-centric practices. As the visionary founder of GreenStreet since 1997, Peter has consistently upheld the brand's image of high customer satisfaction and professionalism.

Widely recognized as a subject matter expert in real estate mortgage and small business financing, Peter's expertise extends across all facets of lending, relationship marketing, operations, and re-engineering workflows. His dedication to delivering unparalleled value to clients has fostered numerous successful, long-term relationships, firmly establishing GreenStreet as a trusted name in the industry.

Beyond his professional achievements, Peter is celebrated for his caring character and natural motivational prowess. This extends to his role as a mentor to GreenStreet teammates and, outside the office, as a cherished grandfather to four adoring grandchildren.

Peter's contributions have not gone unnoticed in the media, with interviews by various business and financial publications highlighting his insights. Quoted in the Long Island Business News and profiled in "Who’s Who in The Mortgage Industry," he has also been featured on Newsday and Channel News 12 Long Island. Peter's commitment to exceeding expectations sets him apart as a respected industry expert dedicated to the success of his clients and the lasting legacy of GreenStreet.

Brian Halbeisen

Chief Operating Officer

Brian is an experienced finance and lending professional with over 25 years of experience in the industry. He has worked with Fintech startups and global Investment Banks and has been involved in building and managing various teams focused on capital markets, trading, underwriting, processing, risk controls and guidelines. Brian is also a founder of Greenstreet Capital Partners, where he specializes in originations, underwriting, and all capital market activities. He began his career at Lehman Brothers as an associate in lending operations and worked his way up to become the Chief Credit Officer of Lehman Brothers Bank. After Lehman, Brian joined Sharestates Investments as the Chief Credit Officer, where he was responsible for credit, underwriting, risk ratings, and capital markets/trading activities.

William Lawrence

Chief Strategy Officer

William Lawrence serves as GreenStreet Capital Partners' Chief Strategy Officer working with the executive team to improve business operations and implement growth strategies. Prior to joining GreenStreet, William first began his career working in M&A, Alternative Investment Services, and Corporate Finance. In 2020, William joined Wall Street veterans at Primestone Partners to help launch a new division, Primestone Housing Solutions, as a founding member. During his time with Primestone Housing Solutions, he created a sales pricing program/model for the team, helped develop relationships with Fortune 500 companies, and managed global sales projects. After Primestone Partners acquired the technology company, Zenya, William began working with their founder to optimize the tech product and scale for future growth.  William is a University of Florida graduate and a passionate Gators sports fan.  In addition, you can find him watching pro sports, playing hockey, or on the golf course.