(Recasts with US trading, adds analyst comment, updates prices, changes byline/dateline, pvs PARIS/CANBERRA)

* Looming rain in Brazil sends soy down more than 1.5%

* Wheat sets two-week low on weak demand

* Corn rises after early decline

CHICAGO, Nov 16 (Reuters) - Chicago soybean futures tumbled on Thursday as the prospect of downpours in Brazil helped offset concerns over hot, dry weather threatening crops in the top exporting nation.

Chicago Board of Trade (CBOT) corn turned slightly higher after early losses, while weak demand pushed wheat down 1.3% as the market hit a two-week low in early trading.

The most-active soybean contract on the CBOT was down 1.71% at $13.61-1/4 a bushel by 1638 GMT. The market extended a setback after the contract on Wednesday reached $13.98-1/2, its highest since Aug. 30, before closing lower.

Soybeans have rallied since the middle of October, supported by drought conditions in northern and central Brazil. However, rains in the forecast next week have eased worries over how the weather in key planting areas could hurt production.

A large harvest in Brazil could limit global demand for U.S. soybeans, said Darin Fessler, a market strategist with Lakefront Futures.

"If Brazil does have a good crop, when we start looking at our ... prices in January, February and on, we're not all that competitive versus Brazil," Fessler said, adding that any loss in crops in Brazil may be made up by an increase in production in Argentina.

Total weekly U.S. soybean export sales last week were the highest since 2012 after a surge in Chinese buying. The U.S. government separately reported private sales of 220,000 tons of U.S. 2023/24 soybeans to unknown destinations.

"There's still a larger lingering cloud about how strong China's economy is and do they really step back up into the buying of commodities," Fessler said. "I think what we've seen recently and probably some goodwill offerings, maybe some hedging by the Chinese."

CBOT corn rose 2 cents to $4.72-3/4 a bushel. CBOT wheat was down 7 cents at $5.53-1/2 a bushel, after earlier touching its lowest price since Oct. 2.

The USDA's report on weekly export sales of U.S. 2023/24 corn was above a range of trade expectations while sales of wheat were below expectations. (Additional reporting by Gus Trompiz in Paris and Peter Hobson in Canberra; Editing by Kirsten Donovan)