* Soybeans up after 3 days of falls
* Wheat down nearly 4% for the week
* Corn on course for 0.5% weekly loss
By Colin Packham
SYDNEY, May 15 (Reuters) - U.S. soybean futures edged higher on Friday from a one-week low hit in the previous session, but were on track to post their biggest weekly drop in a month amid expectations for ample supplies and tepid global demand.
Wheat was also poised to mark its biggest weekly slide in a month, while corn was on course for a half a percent drop.
The most-active soybean futures on the Chicago Board Of Trade rose 0.2% to $8.38-1/2 a bushel by 0106 GMT, after three straight sessions of falls.
It closed 0.3% lower on Thursday, when prices hit their lowest since May 7 at $8.35 a bushel. For the week, soybeans were down nearly 1.5%.
“We know China has bought huge numbers of Brazilian beans, which raises questions about demand for U.S. supplies,” said Phin Ziebell, agribusiness economist, National Australia Bank.
“When you couple this with expectations for bigger production in the United States, that leads to lower prices.”
The United States Department of Agriculture (USDA) said on Thursday private exporters sold 198,000 tonnes of U.S. soybeans to China.
China is set to speed up purchases of U.S. farm goods and will implement the Phase-1 trade deal with the United States, state-owned agriculture trading house COFCO said.
The most active corn futures were down 0.1% to 3.17-1/4 a bushel after closing 0.2% lower on Thursday. Corn was down 0.6% for the week, having closed little changed last week.
The USDA this week projected that U.S. farmers would grow a record-large corn crop this year approaching 16 billion bushels, potentially building domestic stockpiles of the feed grain to their highest levels in 33 years.
Some analysts question whether farmers will plant the full 97 million acres of corn that the USDA forecast, given a steep slide in cash and futures prices since March.
Private analytics firm IEG Vantage pegged U.S. corn seedings at 94.2 million acres.
The most active wheat futures were up 0.1% at $5.02-3/4 a bushel after closing little changed on Thursday. Wheat was down nearly 4% for the week.
The decline comes as beneficial rains this month have put Russia, Ukraine and Kazakhstan, all major Black Sea producers, back on track for large new-crop wheat exports after a dry April, analysts said. (Reporting by Colin Packham; Editing by Subhranshu Sahu)