SINGAPORE - Freight rates for capesize bulk carriers may firm next week as a combination of buoyant cargo volumes, tighter tonnage supply and bad weather could push rates higher, ship brokers said. “There is a lot of cargo volume in the Pacific,” a Singapore-based capesize broker said on Thursday. “There hasn’t been a huge amount of action (from Brazil or Saldanha Bay) but it’s getting tight on ships,” the broker added. Bad weather this week off the coast of China could temporarily halt cargo unloading, causing port congestion, which may force charterers to hire substitute vessels at higher rates if vessel sailing schedules are disrupted, another capesize broker said. “Rates could push up,” the Singapore broker said. Owners this week resisted moves by Brazilian miner Vale to fix cargoes from Brazil to Asia at below market rates on the expectation that freight rates could climb, the broker said. “The market is firm,” a Shanghai capesize ship broker said. Charter rates for the Western Australia-China route were around $5.40 per tonne on Wednesday, slightly higher than $5.20 last week. Freight rates hit $5.80 per tonne on June 24, the highest since Dec. 9. Rates for the Brazil-China route were around $12.20 on Wednesday, a touch lower than $12.27 per tonne a week earlier. They hit $13.18 on June 25, the highest since Dec. 15. Freight rates for smaller panamax vessels continued to climb this week to a near-seven-month high on positive ship owner sentiment due to bouyant South American grain cargoes, a Singapore-based panamax ship broker said on Thursday. Rates for a transpacific voyage, which have gained more than 30 percent since June 2, rose to $6,610 per day on Wednesday, up from $6,059 per day on the same day last week, the highest level since Dec. 15. “The market is feeling pretty good,” the panamax broker said. Owners could expect $7,500 per day to transport a coal cargo from Australia to China, with potentially higher rates for more modern, fuel efficient tonnage, the broker said. But rates could fall in the next few weeks as vessels unload their South American grain cargoes and join the pool of ships seeking new charters, the broker said. Freight rates for smaller supramax vessels were stable at around $6,800 per day for a roundtrip voyage, Norwegian ship broker Fearnley said in a note on Wednesday. The Baltic Exchange’s main sea freight index was up at 840 on Wednesday, campared with 794 last week. (Reporting by Keith Wallis; Editing by Sunil Nair)