KHARTOUM, May 5 (Reuters) - Sudan said on Wednesday it signed an agreement to clear arrears to the African Development Bank through a $425 million bridge loan provided by Britain, Sweden and Ireland. Sudan also signed an agreement to receive a $207 million grant from the bank to support economic reforms, it said. Reporting by Khalid Abdelaziz, writing by Nafisa Eltahir; editing by John Stonestreet Our Standards: The Thomson Reuters Trust Principles.