GRAINS-Soybeans firm, set for biggest weekly gain in 7 months

* Soybeans supported as dry weather threatens Argentina production

* Corn firms, set for fifth straight weekly gain

* Wheat firms, set to finish week up more than 3 percent

SYDNEY, Feb 16 (Reuters) - U.S. soybean futures edged higher on Friday and were poised for its biggest weekly gain in seven months as dry weather threatens production of the oilseed in Argentina. Corn edged higher, while wheat firmed nearly 0.5 percent to be on course for a weekly gain of more than 3 percent. The most active soybean futures on the Chicago Board Of Trade were up 0.1 percent to $10.24-3/4 a bushel after closing up 0.7 percent in the previous session. Soybeans are up more than 4 percent for the week, the biggest weekly gain since July 2017. "Weather forecasters still expect light rains that are well short of the soaking that some of Argentina needs to arrest declining crop conditions," said Tobin Gorey, director of agricultural strategy at the Commonwealth Bank of Australia. Argentina could harvest fewer than 50 million tonnes of soybeans in the 2017-2018 crop year, the lead analyst at the Rosario grains exchange said on Wednesday, as a prolonged drought looks set to continue harming yields. The dryness in the heart of Argentina's Pampas grains belt is likely to persist through the second half of February, climate experts said. The most active wheat futures were up 0.4 percent to $4.63-3/4 a bushel after closing up 1.3 percent in the previous session. Wheat is up more than 3 percent for the week, extending five-week gains to more than 10 percent. The most active corn futures was up 0.1 percent to $3.68-1/4 a bushel after firming 0.1 percent in the previous session. Corn is up more than 1.5 percent for the week, the fifth straight weekly gain. The U.S. Agriculture Department on Thursday said weekly export sales of corn totalled 2.072 million tonnes, topping market forecasts that ranged from 1 million to 1.6 million tonnes.

Grains prices at 0430 GMT

Contract Last Change Pct chg Two-day chg MA 30 RSI CBOT wheat 463.75 2.00 +0.43% +1.76% 441.16 61 CBOT corn 368.25 0.50 +0.14% +0.27% 357.52 71 CBOT soy 1024.75 0.50 +0.05% +0.74% 984.50 76 CBOT rice 11.95 $0.00 +0.00% -2.45% $12.20 25 WTI crude 61.65 $0.31 +0.51% +1.73% $63.19 49


Euro/dlr $1.255 $0.004 +0.32% +0.78% USD/AUD 0.7963 0.002 +0.25% +0.50%

Most active contracts Wheat, corn and soy US cents/bushel. Rice: USD per hundredweight RSI 14, exponential

(Reporting by Colin Packham; Editing by Sunil Nair)