SINGAPORE, Feb 3 (Reuters) - Chicago soybean futures edged lower in early Asian trading on Friday, but were poised for weekly gains supported by uncertainty over supply from top producer Argentina amid dry weather conditions.

Wheat and corn also fell, extending losses to a second consecutive session.

FUNDAMENTALS

* The most-active soybean contract on the Chicago Board of Trade (CBOT) lost 0.5% to $15.26-3/4 a bushel, as of 0200 GMT.

* Wheat gave up 0.4% to $7.58-1/4 a bushel and corn lost 0.3% to $6.73-1/2 a bushel.

* For the week, soybeans are up 1.1%, corn has declined about 1.4% and wheat has lost 10%.

* Grain markets are watching for evidence of a pickup in demand in China, the world's biggest soybean importer, following the week-long Lunar New Year holiday.

* A weekly report from the U.S. Department of Agriculture (USDA) on Thursday showed that export sales of soybeans totalled 928,000 tonnes in the week ended Jan. 26, down from 1.275 million tonnes in the week prior.

* The report also showed corn export sales of 1.756 million tonnes and wheat export sales of 168,900 tonnes.

* Argentina's Buenos Aires grains exchange warned on Thursday that despite recent rainfall, a historic drought over the country's core agricultural region could still negatively impact the current soybean harvest.

* U.S. farmers expanded plantings of winter wheat by 11% from a year ago to an eight-year peak, encouraged by high prices tied to concerns over food supplies following Russia's invasion of major wheat producer Ukraine, as well as relatively low input costs and expanded crop insurance programs.

* Global commodities trader Cargill Inc closed its grain elevator in Portage, Indiana, on Tuesday, according to the company's website.

* Commodity funds were net buyers of CBOT soybean, soymeal, soyoil and wheat futures contracts on Thursday, and net sellers of corn futures contracts, traders said.

MARKET NEWS

* Asian shares turned lower and the dollar regained some posture on Friday, as disappointing earnings from U.S. tech giants undermined sentiment, adding to caution ahead of the high-stakes U.S. non-farm payrolls data.

DATA/EVENTS (GMT)

0145 China Caixin Services PMI Jan

0500 India S&P Global Svcs PMI Jan

0850 France S&P Global Serv PMI Jan

0850 France S&P Global Comp PMI Jan

0855 Germany S&P Global Serv PMI Jan

0855 Germany S&P Global Comp PMI Jan

0900 EU S&P Global Serv PMI Jan

0900 EU S&P Global Comp PMI Jan

0930 UK Composite Final PMI Jan

0930 UK Reserve Assets Total Jan

1330 US Non-Farm Payrolls Jan

1330 US Unemployment Rate Jan

1445 US S&P Global Comp PMI Jan

1445 US S&P Global Svcs PMI Jan (Reporting by Matthew Chye; editing by Eileen Soreng)