ABUJA/CONAKRY, Aug 13 (Reuters) - Coup leaders in Niger are open to diplomacy to resolve a standoff with West Africa's regional bloc, a group of senior Nigerian Islamic scholars said on Sunday after meeting the junta in Niamey. At stake is not just the fate of Niger - a major uranium producer and Western ally in the fight against the Islamists - but also the influence of rival global powers with strategic interests in the region. Western powers fear Russia's clout could increase if the junta in Niger follows Mali and Burkina Faso, which ejected the troops of former colonial power France after coups in those countries