BEIJING, Sept 10 (Reuters) - Chinese banks extended 1.22 trillion yuan ($189.51 billion) in new yuan loans in August, up from July but falling short of analysts’ expectations as markets debate over whether more stimulus is needed to shore up slowing economic growth. Analysts polled by Reuters had predicted new yuan loans would rise to 1.30 trillion yuan in August from 1.08 trillion yuan the previous month and against 1.28 trillion yuan a year earlier. Broad M2 money supply grew 8.2% from a year earlier, central bank data showed on Friday, below estimates of 8.4% forecast in the Reuters poll. M2 grew 8.3% in July from a year ago. Outstanding yuan loans grew 12.1% in August from a year earlier compared with 12.3% growth in July. Analysts had expected 12.3% growth. ($1 = 6.4376 Chinese yuan renminbi) (Reporting by Judy Hua and Kevin Yao; Editing by Kim Coghill) Our Standards: The Thomson Reuters Trust Principles.