Exhibit 99.1 FOR IMMEDIATE RELEASE Portman Ridge Finance Corporation Announces First Quarter 2024 Financial Results Reports Net Investment Income of $0.67 per share and Net Asset Value of $22.57 Per Share Continued Share Repurchase Program: Total of 51,015 Shares for an Aggregate Cost of Approximately $1.0 Million Repurchased During the First Quarter; Accretive to NAV by $0.02 Per Share Announces Second Quarter 2024 Quarterly Distribution of $0.69 Per Share NEW YORK, May 8, 2024 – Portman Ridge Finance Corp ...