SHANGHAI, Aug 24 (Reuters) - China"s market regulator said on Tuesday it has approved Tencent Holdings" (0700.HK) plan to purchase an equity stake in Chinese animation company Studio 9. The State Administration for Market Regulation made the announcement on its website. Tencent, which was already an investor in Studio 9, reported its plan to purchase additional shares from another shareholder to the regulator, according to a separate statement published in June. The statements did not give financial details of the deal.