Founder and Managing Partner of Serengeti Asset Management, a value-driven investment firm that focuses on niche credit opportunities defined by their small size and complexity. It invests in performing debt and high-yielding opportunities. Serengeti provides institutions and private company executives with sophisticated solutions to funding challenges. Investments can include steady debt, liquidations, litigation finance, stressed and distressed corporate and sovereign debt, off-the-run structured credit, reinsurance, and financing platforms.

Prior to launching Serengeti in 2007, Mr. LaNasa was a partner at Goldman Sachs where he headed the Multi-Strategy Investing Business (“MSI”) in the Special Situations Group. MSI was a multi-billion dollar proprietary investment business focused on similar opportunities.

Mr. LaNasa graduated from Harvard Law School (J.D. magna cum laude) and Georgetown University’s School of Foreign Service (B.S.F.S. summa cum laude). He was an attorney at Wachtell Lipton Rosen & Katz in their creditors’ rights and corporate departments and clerked for Judge Adrian G. Duplantier of the U.S. District Court for Eastern District of Louisiana (New Orleans).

He serves on Harvard Law School’s Advisory Board and now serves on the Advisory Board for Georgetown University’s School of Foreign Service and previously served on Georgetown’s Board of Regents.


Leslie D. Biddle is a partner and the president of Serengeti where she heads the firm’s research efforts and risk committee. Prior to joining Serengeti, Ms. Biddle was the Global Head of Commodity Sales at Goldman Sachs and member of the senior commodities management team contributing to the growth of the business from approximately $450 million to more than $3 billion. She was a member of Goldman’s firmwide Finance Committee, Business Practices Committee, New Activity Committee, Structured Investment Products Committee and European Audit and Compliance Committee. She was named managing director in 2004 and partner in 2006. While at Goldman, Ms. Biddle was the architect of many structured transactions in the private equity and energy sectors including the monetization of Allegheny DWR Contract, the financing for the Calpine Construction Finance Facility, the Texas Genco acquisition, Northern Tier Energy and the TXU leveraged buyout, among others.

Prior to joining Goldman Sachs, Ms. Biddle was a Vice President at the AES Corporation focusing on project finance and power plant development and acquisitions. She also served as a vice president at the Overseas Investment Corporation, providing political risk insurance and financing to U.S. companies expanding overseas.

She holds an A.B. from Colby College where she previously served as Vice Chair of the Board of Trustees. She is a member of the Board of Directors of the Empire State Realty Trust (NYSE), CenterPoint Energy (NYSE) and the Advisory Board of NatureVest, the impact investing arm of The Nature Conservancy. Ms. Biddle was twice named to the Hedge Fund Journal’s Top 50 Women in Hedge Funds, is a member of the Council on Foreign Relations and the Global Advisory Board of The Hawthorn Club for executive woman in energy. She lives in New York, New York with her husband, George, and their three children.


Robert Sumberac is the Chief Operating Officer, Chief Financial Officer and Senior Managing Director at Serengeti Asset Management.

Prior to joining Serengeti, Mr. Sumberac was Chief Financial Officer and Managing Director at D.B. Zwirn & Co, a global multi-strategy alternative investment firm. He joined D.B. Zwirn just prior to the in-house discovery of reporting and accounting issues and was instrumental in the forensic review and correction of these issues and the restructuring of the firm’s procedures, processes and back office organization. Prior to that, he was Treasurer and Corporate Controller at Cantor Fitzgerald. Previously, Mr. Sumberac was a Vice President at Goldman Sachs in the Firmwide Funding group where he focused on accounting and treasury issues.

Mr. Sumberac received his B.B.A. in Accounting from the University of Notre Dame.

A.J. joined Serengeti in June 2018. Prior to joining Serengeti, A.J. was an attorney in the litigation department at Wachtell, Lipton, Rosen & Katz, where his practice focused on the litigation and negotiated resolution of disputes relating to distressed debt, corporate governance, and the financial services industry. Before his time at Wachtell Lipton, A.J. was a clerk for Judge John T. Noonan, Jr. of the U.S. Court of Appeals for the Ninth Circuit and an associate at Cravath, Swaine & Moore, LLP.

A.J. graduated cum laude from New York University School of Law. He also holds an M.Phil. in History from Cambridge University and an A.B. in History from Princeton University.