BEIJING, Sept 11 (Reuters) - Chinese banks extended 1.21 trillion yuan ($170 billion) in new loans in August, up from July and exceeding analyst expectations.

Analysts polled by Reuters had predicted new yuan loans would rise to 1.20 trillion yuan in August, up from 1.06 trillion yuan the previous month and compared with 1.28 trillion yuan a year earlier.

Broad M2 money supply in August grew 8.2% from a year earlier, central bank data showed on Wednesday, above estimates of 8.1% forecast in the Reuters poll. It rose 8.1% in July.

Outstanding yuan loans grew 12.4% from a year earlier, slower than July's 12.6%. Analysts had expected 12.4% growth.

Despite a flurry of growth boosting measures since last year, including a push by regulators to ramp up lending, domestic demand in China has remained sluggish, while escalating Sino-U.S. trade tensions weighed on exports.

($1 = 7.1164 Chinese yuan) (Reporting by Beijing Monitoring Desk Editing by Jacqueline Wong)