BERLIN, April 21 (Reuters) - Germany’s constitutional court paved the way on Wednesday for the country to sign off legislation ratifying the European Union’s Recovery Fund as it dismissed legal challenges against the debt-financed investment plan. The decision is essential for launching the bloc’s 750 billion euro ($900 billion) recovery spending to mitigate the consequences of the COVID-19 pandemic. ($1 = 0.8331 euros) (Reporting by Kirsti Knolle, editing by Maria Sheahan)