By Amber Murray Ocado has announced KKR chair Adam Warby will succeed Rick Haythornthwaite as its chairman in December. As well as chairing KKR, Warby also serves as chair of management consultant firm Heidrick & Struggles, and previously held various positions at Microsoft and IBM. Earlier this year, Ocado said Haythornthwaite would step down to focus on his role as chair of Natwest, a position he has held since last September. However, the appointment of his successor has come sooner than initially thought; Haythornthwaite had previously said he would step down next April at the firm’s annua…