Updates with European trading, changes dateline

BEIJING/PARIS, June 29 (Reuters) - Corn led a drop in Chicago grain futures on Monday as traders adjusted positions before closely watched U.S. planting and stocks data while monitoring forecasts of a hot spell in the U.S. Midwest.

The U.S. Department of Agriculture's acreage and quarterly grain stocks reports on Tuesday are among the most closely watched publications in grain markets, giving a pointer in particular to U.S. corn and soybean supply prospects for the coming season.

Market participants on average expect the USDA to revise down its corn area estimate and increase its soybean planting view, reinforcing a shift from corn to soybeans.

"Even so, there are still many in the market who do not believe the corn area has fallen much from last year," said CM Navigator analyst Donatas Jankauskas.

July corn CN26 on the Chicago Board of Trade was down 1.9% at $4.05 a bushel by 1158 GMT after setting a contract low at $4.03-1/2.

CBOT wheat Wv1 was down 0.5% at $5.86-3/4 a bushel while CBOT soybeans Sv1 were 0.8% down at $11.47-1/4 a bushel.

Grain futures came under pressure last week as a dollar rally and falling crude oil fuelled selling by investment funds in the run-up to the USDA's June 30 data.

Monday's weakness in grains came despite an easing in the dollar index .DXY and a steadying of crude oil LCOc1 after tit-for-tat strikes by the U.S. and Iran that underscored the fragility of their interim peace deal.

Soybean and corn prices often track crude oil because of their role in biofuel production.

The resumption of fertiliser shipments through the Strait of Hormuz could remove some input-cost premium from the market because the waterway handles a large share of global fertilisers and related inputs.

Hot weather in much of the U.S. Midwest this week is being monitored, though regular showers and a projected easing of temperatures next week were tempering concerns about crop stress.

Swift harvest progress in the United States, along with strong production prospects in the Black Sea export region, were also weighing on the wheat market, taking attention away from a severe heatwave in Western Europe over the past week.

Prices at 1158 GMT
	Last	Change	Pct Move
CBOT wheat Wv1	586.75	-3.00	-0.51
CBOT corn Cv1	405.00	-7.75	-1.88
CBOT soy Sv1	1147.25	-9.00	-0.78
Paris wheat BL2c1	204.25	1.50	0.74
Paris maize EMAc1	234.00	5.75	2.52
Paris rapeseed COMc1	513.25	0.00	0.00
WTI crude oil CLc1	69.89	0.66	0.95
Euro/dollar EUR=	1.14	0.00	0.23
Most active contracts - Wheat, corn and soy U.S. cents/bushel, Paris futures in euros per metric ton