LONDON, Sept 29 (Reuters) - British asset manager Rathbones said it had appointed Iain Hooley as its chief financial officer, as Jennifer Mathias steps down from the role and the board to take the newly created position of group chief of staff.

Her move will help support the company's acquisition of the UK wealth business of Investec, Rathbones said on Friday.

Rathbones announced the deal in April, in an all-share transaction that valued the Investec unit at 839 million pounds ($1.03 billion), as firms in the high-growth wealth sector look to scale up in the face of higher costs.

Hooley joins from the Investec Wealth side of the deal, where he was finance director for more than a decade and most recently CEO of the UK unit.

($1 = 0.8177 pounds) (Reporting by Lawrence White Editing by Mark Potter)