The dollar selling was aimed to prevent the spot yuan from breaching the key 7.25 per dollar level, sources said, noting the local unit was weakening towards its daily downside limit.

China's onshore yuan is allowed to trade in a narrow range of 2% on either side of the daily midpoint fixing. Friday's fixing allows the onshore yuan to trade in a range between 6.9762 and 7.2610.

(Reporting by Shanghai and Beijing Newsroom; Editing by Alex Richardson)