SHANGHAI/BEIJING, Sept 6 (Reuters) - China’s major state-owned banks were seen buying U.S. dollars in the onshore spot market late on Friday, pushing the yuan lower before the close of trade, three sources with direct knowledge of the matter said. The onshore spot yuan strengthened on Friday amid dollar weakness after disappointing U.S. jobs data. The move by the state banks was seen as an effort to rein in rapid yuan appreciation, with one source saying the aim was to ensure the currency closed on the weaker side of the 6.45 per dollar level. The onshore yuan finished Friday’s session at 6.4585 per dollar after rising to a high of 6.4305, the strongest since July 17. The dollar came off its immediate post-payrolls lows on other currencies as the New York session wore on.