 SoftBanks Z Holdings Corp 4689.T is in talks to merge with messaging app operator Line Corp 3938.T, two sources said on Wednesday, the investment companys latest bet on a struggling tech firm. A deal could see SoftBank Corp 9434.T, which controls internet firm Z Holdings, and Lines parent Naver Corp 035420.KS form a 50:50 venture that would control Z Holdings, which would in turn operate Line and Yahoo, the sources said. 