PARIS/SINGAPORE- Chicago soybean futures headed back towards an eight-month peak on Wednesday as the market awaited a U.S. government report for a latest indication on weather damage to South American crops.

Corn edged up and wheat ticked lower while investors adjusted positions before the U.S. Department of Agriculture's (USDA) world supply and demand forecasts later on Wednesday.

The most-active soybean contract on the Chicago Board of Trade (CBOT) Sv1 was up 0.8% at $15.80-3/4 a bushel by 1228 GMT, trading near Monday's eight-month high of $15.89-1/2.

Crop watchers have been scaling back forecasts for Brazil and Argentina's soybean harvests after drought, raising the prospect that some international demand will shift towards U.S. supplies.

Analysts at hEDGEpoint Global Markets said on Wednesday they had cut their outlook for Brazil's soybean crop by about 5 million tonnes to 133.3 million tonnes. 

"South American weather is the focus right now," said Phin Ziebell, agribusiness economist at National Australia Bank. "Crop losses can send prices higher."

Brazil is now expected to export 7.5 million tonnes of soybeans in February, industry group ANEC said on Tuesday, down from 9.923 million tonnes projected a week earlier. 

A run of U.S. export sales has underscored expectations that shipments from the United States will pick up. 

A sharp rise in palm oil, which competes with soyoil in vegetable oil markets, also supported soybeans as traders reacted to Indonesian export restrictions.

CBOT corn added 0.6% to $6.36 a bushel and wheat edged down 0.3% to $7.76-1/4 a bushel.

The corn market is also awaiting the USDA's estimates on South American supply, as well as any adjustments to Chinese demand.

Wheat found support on Tuesday from a lower than expected official estimate of Canada's stocks, but global export competition and normal activity in Black Sea markets, despite geopolitical tensions over Ukraine, were capping prices.

(Reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; Editing by Shailesh Kuber and Tomasz Janowski) ((gus.trompiz@thomsonreuters.com; +33 1 49 49 52 18; Reuters Messaging: gus.trompiz.thomsonreuters.com@reuters.net))