CANBERRA, Jan 12 (Reuters) - Chicago soybean futures climbed on Friday ahead of a U.S. government crop data release that could shift the market, although prices were set for a fourth straight weekly loss due to weak demand for U.S. exports and an improved supply outlook.

Corn futures inched lower and were on track for a fifth straight weekly decline amid ample supply.

Wheat futures rose, but were poised for a second straight weekly loss.

FUNDAMENTALS

* The most-active soybean contract on the Chicago Board of Trade (CBOT) was up 0.4% at $12.41-1/4 a bushel, as of 0136 GMT, after slipping to $12.34 on Tuesday and Thursday, its lowest since December 2021. The contract lost 1.2% so far this week.

* CBOT corn dipped 0.1% to $4.57-1/2 a bushel after hitting $4.52 on Monday and Tuesday, its weakest since December 2020. It was down 0.7% from last Friday's close.

* Wheat was up 0.3% at $6.05-1/4 a bushel. Still, the contract lost 1.8% for the week, set for its second consecutive weekly fall, and hovered near September's three-year low of $5.40.

* U.S. soybean exports this season are behind last year's level, with Brazil, the biggest producer, dominating the market following a record 2022/23 harvest.

* Dry conditions have hit Brazil's current soybean crop, but recent rains stabilised yields. While forecaster Patria Agronegocios on Thursday predicted a 143.18 million metric ton 2023/2024 harvest, the government's prediction is around 155 million tons, similar to last season.

* Favourable weather is also improving prospects for Argentina's soybean farmers. The Rosario exchange this week raised its 2023/24 soybean estimate to 52 million metric tons.

* Traders were waiting for the release of quarterly USDA grain stocks data and a monthly agricultural supply/demand report later on Friday, which could set the tone for prices for the coming weeks.

* Analysts expect the USDA to report a jump in U.S. corn and wheat stockpiles from a year-ago levels, but lower stocks of soybeans.

* In corn markets, the International Grains Council (IGC) raised its forecast for 2023/24 global corn production by 7 million metric tons to 1.230 billion tons, with higher Chinese production offseting lower expected yields in Brazil.

* The USDA, meanwhile, confirmed private sales of 175,000 metric tons of U.S. corn to Mexico, the first flash sale of corn for weeks.

* For wheat, the IGC increased its 2023/24 world production outlook by 1 million tons to 788 million.

* Algeria's state grains agency OAIC is believed to have purchased around 250,000 to 350,000 metric tons durum wheat in a tender which closed on Wednesday, European traders said.

* USDA data showed that net U.S. wheat export sales in the week ended Jan. 4 were below analysts' estimates. A bumper Russian harvest has kept global markets well supplied in recent months.

* Commodity funds were net buyers of Chicago soybeans on Thursday and net sellers of corn and wheat, traders said.

MARKETS NEWS

Global stock indexes were flat to lower on Thursday as data showed U.S. consumer price inflation above expectations in December, raising doubts that the Federal Reserve will cut rates as soon as some traders expect.

(Reporting by Peter Hobson; Editing by Sherry Jacob-Phillips)