JAKARTA, Feb 5 (Reuters) - Indonesia’s economy shrank slightly more than expected in the fourth quarter and suffered its first full-year contraction in over two decades in 2020 as it grappled with the fallout of the COVID-19 pandemic, official data showed on Friday. Southeast Asia’s largest economy shrank 2.19% year-on-year in the October-December quarter. Economists in a Reuters poll had expected the economy to contract 2% after it slumped 3.49% in the third quarter from a year earlier. On a quarterly, non-seasonally adjusted basis, gross domestic product declined 0.42%, after 5.05% growth in the July-September period. Gross domestic product shrank 2.07% for the full-year of 2020, its first contraction since 1998. Economists in the poll had forecast a 2% slump in 2020, following 5.02% growth in 2019. (Reporting by Fransiska Nangoy and Gayatri Suroyo Editing by Shri Navaratnam)