Dec 20 (Reuters) - The International Monetary Fund said on Monday its executive board has extended Fund debt service relief for 25 eligible low-income countries for another three months until April 13, 2022. The approval of the fifth and final tranche of debt service relief totaling about $115 million follows four prior tranches approved in April and October of 2020 and 2021, the IMF said in a statement on Monday. The tranche completes the two-year COVID-related debt service relief first approved in April 2020, providing relief worth about $964 million to eligible countries. Countries receiving debt service relief in the fifth tranche under the Catastrophe Containment and Relief Trust include Benin, Burkina Faso, Burundi, Central African Republic, Comoros, Djibouti, Ethiopia, Gambia, Guinea, Guinea-Bissau, Haiti, Kyrgyzstan, Lesotho, Liberia, Madagascar, Malawi, Mali, Nepal, Niger, Rwanda, Sao Tome and Principe, Sierra Leone, Solomon Islands, and Tajikistan. Reporting by Kanishka Singh in Bengaluru; Editing by Mohammad Zargham and Stephen Coates