* ASX 200 eases for sixth session as Russia bans Western imports
* 39 shares higher, 149 shares lower, 13 shares unchanged
* Big name banks, miners and food grocers lower (Adds analysis, quotes, stocks on the move)
By Thuy Ong and Gyles Beckford
SYDNEY/WELLINGTON, August 8 (Reuters) - Australian shares retreated further from three-week lows on Friday, after Wall Street extended its losses on concerns the tensions between Russia and the West and tit-for-tat sanctions may hit global growth.
Moscow banned imports of most food from the West on Thursday in retaliation against sanctions over Ukraine, a stronger than expected measure that isolates Russian consumers from world trade to a degree unseen since Soviet days.
"The sanctions are likely to impact countries like Australia the most as agricultural exports are among the top 5 exports," said Evan Lucas, IG's market strategist in a note to clients.
In the food and grocery sector, Wesfarmers Ltd slipped 0.6 percent, and rival Woolworths Ltd gave up 0.7 percent. Goodman Fielder Ltd lost 0.4 percent.
Big name banks lost ground for a second day, with National Australia Bank down 1.2 percent and Westpac Banking Corp declining 0.8 percent.
The S&P/ASX 200 index lost 0.8 percent, or 44 points to 5,462.8 by 0213 GMT to mark the sixth consecutive day in the red, its longest losing streak since early-December.
The market eased 0.1 percent on Thursday and is set to shave off 1.7 percent for the week, its biggest one-week loss since mid-March.
The benchmark hit a six-year high of 5,644.2 on July 31, but has declined nearly 200 points as investors fretted about escalating geopolitical tensions from the conflict in Ukraine and Gaza.
Gold prices rose as safe-haven buying amid rising tensions in Iraq and Ukraine extended the previous session's rally.
This helped limit the broader market losses as Beadell Resources Ltd soared 5.5 percent, while Australia's top gold producer Newcrest Mining Ltd climbed 2 percent.
World no. 2 miner Rio Tinto Ltd edged 0.1 percent higher after topping market forecasts with a 21 percent rise in first-half profit.
News Corp lost 2.5 percent to June lows of A$17.92 as revenue in the company's news and information division fell 6.2 percent to $1.56 billion.
Elsewhere, Australia's central bank on Friday stuck to its mantra of keeping interest rates steady at a record low for some time yet, and played down a shock jump in July's jobless rate to a 12-year high saying there has been significant volatility as of late.
New Zealand stocks were on the backfoot with the benchmark NZX 50 index flirting with four month lows, down 0.5 percent to 5,070.7.
There were modest losses for leading stocks, including Fletcher Building and Spark NZ, the former Telecom Corp, which changed its name on Friday.
Software company Diligent Ltd gained 2.9 percent to NZ$4.32, a six-week high, after it reported a lift in second quarter revenue and raised its full year forecast. (Editing by Shri Navaratnam)