GRAINS-CBOT corn slide slows as USDA report awaited
* Corn under pressure from expectations for larger yields
* Soybeans underpinned by planting delays
* USDA expected to lower U.S. corn acreage estimate
(Adds quotes, updates prices, previous Sydney)
LONDON, June 28 (Reuters) - Chicago new-crop corn futures were slightly lower on Friday as wet weather boosted U.S. yield prospects although the pace of the recent decline slowed with caution ahead of a closely watched U.S. government report due later in the day.
Wheat futures on the Chicago Board of Trade (CBOT) edged higher but also remained on course for a weekly loss, while soybeans were little changed.
CBOT December corn was a marginal 0.2 percent lower at $5.37-1/2 a bushel by 1022 GMT, after closing down 1 percent on Thursday.
"The improving U.S. corn yield prospects are currently bearish for new-crop prices," said Luke Mathews, commodities strategist at Commonwealth Bank of Australia.
Corn is down more than 3 percent for the week on the back of the favourable weather, prompting a monthly loss of 5 percent, the biggest fall in four months.
Despite forecasts for continued crop friendly-weather, analysts said traders are cautious ahead of the U.S. Department of Agriculture (USDA) report, set for release at 1600 GMT.
Analysts expect the USDA to lower its estimate for total corn acreage - due to rains delaying sowing this spring - to 95.313 million acres, having pegged plantings at 97.282 million acres in March.
CBOT soybeans were little changed, underpinned by planting delays.
"Delayed plantings beyond the optimal time can reduce the yield potential and create a higher risk of frost damage before maturity is reached," Rabobank said in a market report.
"However, soil moisture is good throughout the soybean growing area and none of the longer range forecasts indicate excessive dryness in the coming months. Trend line yields are still achievable, assuming growing conditions are good over the next two months," the report added.
CBOT November soybeans fell a marginal 0.02 percent to $12.75 a bushel but remained on track for a small gain on the week of 0.1 percent.
Wheat futures on the CBOT rose with July up 0.4 percent to $6.66-1/4 a bushel. But they are on track for a weekly loss of about 4.5 percent.
"Harvest has commenced in the U.S. (winter wheat), Europe and the Black Sea region with generally favourable production expectations likely to pressure futures lower over the coming months," Rabobank said.
"Overall, global production is set to increase about 40 million tonnes year-on-year, which underpins the bearish outlook for prices. However, the magnitude of Chinese imports will be the biggest supportive factor."
November milling wheat in Paris was unchanged at 196.75 euros a tonne.
(Additional reporting by Colin Packham in Sydney, editing by Jeff Coelho)