GENEVA, March 31 (Reuters) - The World Trade Organization slightly revised up its forecast for growth this year of global goods trade after a decline in 2020 far less severe than its expectation when the coronavirus first struck. The WTO said on Wednesday that it expected merchandise trade would grow this year by 8.0% after a fall of 5.3% last. That compared with figures in October of respectively 7.2% growth and a 9.2% decline. The Geneva-based trade body said that trade growth should slow to 4.0% in 2022, with the effects of the pandemic continuing to be felt and with global trade below its pre-pandemic trend. (Reporting by Philip Blenkinsop, editing by Marine Strauss)