Bain Capital has agreed to sell a 49.9% stake in Bellsystem24 Holding, a Japanese telemarketing firm, to Itochu Corp. Bain Capital will keep its 50.1% stake in Bellsystem24, which it acquired from Citigroup Inc. back in 2009 for $1 billion. Itochu will pay 30 billion yen and will take out loans from its backs to make further payments to complete the acquisition. Bellsystem24, has 20,000 employees in 22 call centers nationwide.