Countries from across the globe were to adopt a landmark convention banning cluster bombs in a formal ceremony here Friday, in a move supporters hope will stigmatise the lethal weapons as much as landmines.Diplomats from 111 countries were to adopt the treaty in a closing ceremony at Croke Park in the Irish capital after 12 days of robust negotiations at the Gaelic games stadium.The convention, agreed Wednesday, outlaws the use, production, transfer and stockpiling of cluster munitions. It also provides for victim welfare and clearing contaminated areas.Politicians and campaigners insisted it was a hugely significant pact despite the absence of key powers like the United States, China and Russia.