CANBERRA, July 18 (Reuters) - Chicago soybean futures held steady on Friday and were on track for a weekly gain of about 2%, supported by hopes for improved U.S. exports and expectations that the U.S. biofuel policy will boost demand for soyoil used as feedstock.

However, prices were still less than $1 a bushel above last year's five-year lows, with plentiful supply from South America and projections of a large U.S. harvest capping gains.

Corn futures inched higher and were headed for a roughly 2% weekly gain due to a wave of bargain-hunting and short-covering earlier in the week, with plentiful supply also weighing on the market.

Wheat climbed but was set for a weekly loss of about 2% amid seasonal pressure from ongoing northern hemisphere harvests.

FUNDAMENTALS

* The most-active soybean contract on the Chicago Board of Trade (CBOT) Sv1 was flat at $10.26-3/4 a bushel, as of 0033 GMT, while CBOT corn Cv1 was up 0.2% at $4.22 a bushel and wheat Wv1 was 0.4% higher at $5.35-3/4 a bushel.

* CBOT soyoil BOc1 rose 0.1% and was headed for a roughly 3.5% weekly gain, having earlier in the week touched its highest level in nearly two years.

* U.S. soybean export sales in the week ended July 10 reached 529,600 metric tons for 2025-26 shipment, the U.S. Department of Agriculture (USDA) said, beating analysts' expectations.

* This week, the USDA also reported a sale of 120,000 tons of U.S. soybeans to "unknown destinations", triggering speculation that China might be the buyer and could buy again.

* A trade deal between the United States and Indonesia could also boost U.S. soy exports.

* However, oilseed lobby group Abiove raised its forecast for Brazil's 2024/25 soybean exports to 109 million tons from 108.2 million tons, and the Rosario Grains Exchange lifted its estimate for Argentina's 2024/25 harvest to 49.5 million tons from 48.5 million tons.

* PepsiCo PEP.O, meanwhile, said it was expanding use of avocado and olive oil across its brands, rather than the canola or soybean oil it uses.

MARKETS NEWS

* Equities advanced on Thursday with the S&P 500 and the Nasdaq registering record closing highs and the dollar rose as investors were encouraged by the latest crop of economic data and earnings reports. Oil futures rose on supply risks in the Middle East. MKTS/GLOB

(Reporting by Peter Hobson; Editing by Subhranshu Sahu)

((peter.hobson@thomsonreuters.com;))