TOKYO (Reuters) -SoftBank Group Corp CEO Masayoshi Son’s stake in the Japanese conglomerate he founded has risen to 29.01% from 26.90% in February following the retirement of treasury shares, regulatory filings showed on Thursday. Son’s stake would be larger if not for the exclusion of shares held by an entity which, according to filings, Son no longer represents after being replaced by his brother Taizo Son. SoftBank completed a record $23 billion share buyback programme this month and has retired most of its treasury shares. The stock has lost 20% since hitting two-decade highs in March. Reporting by Sam Nussey; Editing by Jan Harvey Our Standards: The Thomson Reuters Trust Principles.