SINGAPORE Dec 12 (Reuters) - Rates for capesize bulkcarriers on key Asian routes are set to remain firm going intonext week due to bad weather in Australia and buoyant fixtureactivity by major iron ore miners, ship brokers said on Thursday. Charter rates for voyages from Australia to China werenudging $17 per tonne on Thursday, jumping almost $5 per tonneon the week. The rise was fuelled by miners including Rio Tinto seekingto fix early ships because bad weather in Western Australia haddisrupted sailing schedules, said one Singapore-based shipbroker on Thursday. "The market will hold steady at least into the start of nextweek. It will come off pretty quickly at some stage," said thebroker. He added the latest fixture was concluded at $16.75 pertonne. Benchmark capesize rates from Australia to China closed at $14.46 per tonne on Wednesday up from $12.26 per tonnea week earlier. Capesize rates from Brazil to China jumped to closeat $28.42 on Wednesday against $26 at last Wednesday's close.The last done was at $29.50 per tonne, equivalent to dailyearnings of about $56,000, the highest level since October 2010. It is "exciting times for the big ships as in particulariron ore miners struggle to cover their needs for pre-Christmasloaders from West Australia and early 2014 stems from Brazil,"said Norwegian ship broker Fearnley in a research note onWednesday. Panamax rates are set to hold steady next week even as thenorth Pacific transpacific market remains quiet, said oneSingapore-based panamax broker on Thursday. Buoyancy in the panamax was due to charterers splitting capesize cargoes, especially for coal exports from Australia,into two panamax stems due to higher capesize rates, the brokersaid. The market is also finding support from US grain cargoesand coal exports from India. "I am not sure how much gusto the panamax market has stillgot," the broker warned. Rates for a panamax transpacific voyage closed at$14,091 on Wednesday from $12,433 a week earlier. The last donewas higher at $14,322. Supramax rates remained strong on coal cargoes fromIndonesia, said one supramax broker. The Baltic Exchange's main sea freight index soaredto 2,299 on Wednesday, a rise of 305 points on the week.