Onsemi rises after $6 billion share buyback plan announced
** Chipmaker Onsemi's ON.O shares rise 2.6% to $46.76 premarket ** Co announces $6 billion share repurchase authorization ** New share repurchase program launches on January 2026, spans three years ** Up to last close, stock has fallen 27.7% this year (Reporting by Anhata Rooprai in Bengaluru) ((Anhata.Rooprai@thomsonreuters.com))