Australia shares gain 0.5 pct on strong earnings, miners up

* ASX 200 rises 0.5 percent in broad-based gain

* 159 shares higher, 31 shares lower, 10 shares unchanged (Adds analysis, quotes, stocks on the move)

By Thuy Ong and Gyles Beckford

SYDNEY/WELLINGTON, August 19 (Reuters) - Australian shares were steered higher by a batch of robust earnings results on Tuesday, with support also coming from gains in mining stocks and an upbeat session on Wall Street.

The market started off on a firm footing on a burst of encouraging earnings, led by the likes of Australian steel maker and iron ore miner Arrium Ltd, which soared 8.3 percent after posting an 83 percent jump in annual underlying profit.

Investors also lapped up Amcor Ltd after the firm reported a 25 percent increase in full-year net profit. The stock gained 4.1 percent to 2-1/2 month highs of A$10.70

Insurers edged higher, with Insurance Australia Group Ltd adding 0.4 percent after saying its full year net profit soared 58.9 percent. Suncorp Group climbed 1.3 percent.

"I think overall our trend is still up, at least to date there's no evidence that that will change given the results we've seen so far," said Don Williams, chief investment officer at Platypus in Sydney.

Heavyweight miners BHP Billiton Ltd and Rio Tinto (Xetra: 855018 - news) Ltd jumped 1 percent and 1.4 percent, respectively, as copper edged higher overnight. BHP Billiton (NYSE: BBL - news) is due to report its full year results after the closing bell.

The S&P/ASX 200 index gained 25.5 points, or 0.5 percent, to 5,612.6 by 0310 GMT. The benchmark ended 0.4 percent higher on Monday.

Among other earnings, Toll Holdings Ltd jumped 4 percent to near six-month highs of A$5.62 after the transport and logistics company posted a 5.7 percent increase in annual net profit.

QBE Insurance Ltd (Other OTC: QBEIF - news) was one of the few negatives on the earnings front, as the stock was put on a trading halt after its half year net profit slumped 18 percent to $392 million, hit by higher-than-expected claims in overseas markets.

New Zealand shares followed the strong offshore lead with the benchmark NZX-50 index hitting a near three-week high. It was last trading about 0.9 percent higher at 5,119.27, with session gains the strongest in more than three months.

Gains were led by top stocks, with the biggest company Fletcher Building (NZSE: FBU.NZ - news) 1 percent higher at NZ$9.14, a three week high. Spark, the former Telecom Corp, Contact Energy, and Trade Me (NZSE: TME.NZ - news) all rose more than 1.5 percent.

Fletcher Building and Trade Me, along with Mighty River Power report their annual results on Wednesday.

The biggest decline was a 3.6 percent fall for clothing retailer Hallenstein Glasson to NZ$2.94 as it confirmed its full year profit will plunge 25 percent.

(Editing by Shri Navaratnam)