SYDNEY, Sept 14 (Reuters) - Australia's employment surged in August while its participation rate hit a record high and the jobless rate held steady, in a sign that decade-high interest rates have yet to loosen demand in the drum-tight labour market.

Figures from the Australian Bureau of Statistics on Thursday showed net employment rose 64,900 in August from July, when they fell by an upwardly adjusted 1,400. Market forecasts had been for an increase of around 23,000.

The gains were almost entirely driven by a 62,100 jump in part-time jobs.

The jobless rate held steady at 3.7%, matching forecasts from analysts, while the participation rate surged to 67.0%, the highest since records began in 2013.

The Australian dollar briefly broke above $0.6450 but soon unwound some of the gains, while markets continued to price in the prospect of the Reserve Bank of Australia holding rates steady next month and a decent chance of one final hike early next year.

The labour market has proven remarkably resilient with 410,700 net jobs added in the 12 months to August even as interest rates have climbed 400 basis points to an 11-year high of 4.1%.

"The labour market will eventually cool as activity softens," said Sean Langcake, head of macroeconomic forecasting for Oxford Economics Australia.

"But today's data neither confirm nor deny whether this process has begun in earnest. Firms are still adding to headcount, and with job vacancies still elevated, employment growth will likely hold steady in the coming months."

The RBA has forecast that the jobless rate will hit 3.9% by the end of this year and 4.5% by mid 2025.

(Reporting by Stella Qiu; Editing by Kim Coghill and Sam Holmes)