The sharemarket recovered from opening losses to close slightly higher on cautious optimism US politicians will agree on a temporary deal to raise its debt ceiling.
IG market strategist Stan Shamu said it appeared some sort of deal to avoid a default was close, with reports that a US Senate vote would soon go ahead.
"I think the investment community is cautiously optimistic that something will get done and we'll see the extensions we need," he said.
The benchmark S&P/ASX 200 Index gained 3.8 points to 5262.9, while the broader All Ordinaries edged up 5.2 points to 5264.4.
Resource stocks were the best performers on Wednesday, with iron ore miners the standouts. That was due to recent strong Chinese trade balance figures, and the latest production figures from Rio Tinto showing it was on track to reach its iron ore production target.
Rio gained 91¢, or 1.4 per cent, to $64.11 and BHP Billiton added 38¢, or 1.1 per cent, to $35.78.
Pure-play iron ore miners did even better, with Fortescue Metals up 2.7 per cent to $5.40, Mount Gibson Iron rising 6.5 per cent to 82¢ and Atlas Iron gaining 5.6 per cent to $1.045.
Blood products and vaccines maker CSL improved after announcing a share buyback worth almost $1 billion, adding 88¢ to $66.26.
Ferry and tour boat operator SeaLink Travel has sailed through a stellar first day on the sharemarket, adding $28 million to its value, with its shares rising from the listing quote of $1.10 to close 36.4 per cent higher at $1.50.
SeaLink operates ferries to Kangaroo Island as well as from Townsville and out of Darwin. It also owns the Captain Cook Cruises tour company on Sydney Harbour and offers other tourism services.
SeaLink sold 15 million new shares in its public float to raise $16.5 million, which is to be used to buy new vessels and strengthen its balance sheet for expansion.
The gold price was trading at $US1281.35 an ounce, up $US11.86.
The dollar remained firm, though eased to close slightly lower on the day at US95.25¢, from US95.32¢.
On the bond market, prices dipped before the US debt deadline. The December 10-year bond futures contract was trading at 95.790 (implying a yield of 4.210 per cent), down from 95.830 (4.170 per cent) on Tuesday. The three-year contract was at 96.800 (3.200 per cent), from 96.810 (3.190 per cent).