PARIS, June 29 (Reuters) - Euronext wheat edged lower on Monday as traders weighed potential heatwave-related yield losses in France against prospects for a bumper harvest in the rival Black Sea export region.

Maize futures, meanwhile, jumped to fresh contract highs as a warm, dry outlook for early July risked further straining French crops already hurt by the scorching heat of the past week.

September wheat BL2U6 on Paris-based Euronext was down 0.3% at €202.25 ($231.09) a metric ton at 1621 GMT, hovering around a one-week low.

Wheat had rallied to a four-week peak last Wednesday during a record heatwave in France.

But with French wheat expected to be less affected than maize, and high volumes in the Black Sea zone likely to offset losses in France, Euronext prices have lost momentum.

Initial reports from barley and wheat harvesting in France indicated some disappointing but not dire yields along with good grain quality, industry group Intercereales said on Monday.

Argus has raised its forecast for Russian wheat production in 2026/27 to the highest since the record 2022/23 harvest, it said on Monday.

Russian wheat export prices fell again last week as the harvest got under way, according to analysts.

Chicago wheat Wv1, meanwhile, fell as traders adjusted positions before U.S. Department of Agriculture acreage and stocks reports on Tuesday that are among the most closely watched publications in grain markets. GRA/

Maize prices on Euronext, however, resumed their rally. New-crop November maize EMAX6 was up 2% at €225.50 a ton, after setting a contract high of €226.75.

"Maize is thinly traded and there's talk of a historic low for French production at 9 million tons," a futures dealer said.

The French agriculture ministry said last week that volumes this year could drop by 30%, suggesting a crop below 10 million tons, with a growers association warning losses could be more severe.

Prices at 1621 GMT
	Last	Change	Pct Move
Paris wheat BL2U6	202.25	-0.50	-0.25
Paris maize EMAc2	225.50	4.50	2.04
Paris rapeseed COMc1	512.75	-0.50	-0.10
CBOT wheat Wv1	582.00	-7.75	-1.31
CBOT corn Cv1	400.75	-12.00	-2.91
CBOT soy Sv1	1138.75	-17.50	-1.51
WTI crude oil CLc1	70.76	1.53	2.21
Euro/dollar EUR=	1.14	0.00	0.36
Most active contracts - Wheat, corn and soy U.S. cents/bushel, Paris futures in euros per metric ton

($1 = 0.8752 euros)