Spain’s Telefonica de Espana SA says it is in the final stages of talks to sever its alliance with Unisource but a final deal has yet to be agreed. We can reach a deal by the end of the year. The talks are very advanced, but I can’t give you concrete terms on amounts and conditions, CEO Javier Revuelta told Reuters. Telefonica decided to ditch Unisource in favor of the Concert alliance with British Telecommunications Plc and MCI Corp – an alliance whose future is shrouded in uncertainty after WorldCom Corp shattered its hoped of a significant presence in the US market.