* Dry weather in France, Germany seen threat to wheat yields
* U.S. corn plantings running behind five-year average pace
(Adds quotes, updates prices)
LONDON, April 15 (Reuters) - Wheat prices on the Chicago Board of Trade edged higher on Tuesday, moving back towards the prior session's two-week peak, boosted by cold, dry weather in the U.S. Plains and political tensions in major grain exporter Ukraine.
Corn prices eased slightly, erasing most of the prior session's gains, with a slower-than-normal start to U.S. plantings not yet a significant concern. Soybeans made modest gains.
Chicago Board of Trade wheat for May delivery rose 0.3 percent to $6.80-3/4 a bushel by 1005 GMT, after climbing 2.8 percent on Monday, when it touched a near two-week high of $6.89-1/2.
The U.S. National Weather Service warned of freezing conditions for Tuesday across wheat-growing areas in western Oklahoma and parts of northern Texas. Winter wheat becomes more vulnerable to freeze damage as it matures in the spring.
"Cold and dry conditions on the U.S. Plains are a concern for the wheat market," said Paul Deane, agricultural commodity strategist at ANZ in Melbourne.
"A brief cold snap across the Midwest is forecast, pushing deep into the south, with record low temperatures possible in Texas. On top of that the 15-day weather outlook is for continued below average rainfall across the major Hard Red Winter wheat states."
The U.S. Department of Agriculture rated the winter wheat crop at 34 percent good to excellent, 1 percentage point below last week and two points below a year ago, broadly in line with market expectations.
Prices in western Europe have been supported by dry weather in France and Germany with May wheat in Paris climbing to a peak of 214.25 euros on Monday, its highest level in nearly four weeks.
The contract was off a marginal 0.1 percent at 213.75 euros a tonne on Tuesday.
"If the drought in western Europe persists, this could have a negative impact on yields," Commerzbank said in a market note.
"This year's wheat crops in Russia and the Ukraine are also at risk from the ongoing drought and more difficult financing conditions due to the political uncertainty."
Ukraine and Russia, among the world's largest grain exporters, have struggled to raise financing to sow spring grains including maize, with lenders tightening payment procedures due to the instability in the region.
CBOT May corn slipped 0.55 percent to $5.00-1/4 per bushel while May soybeans gained 0.4 percent to $14.81-3/4 a bushel.
A cool spring is slowing the pace of U.S. corn planting but a turn to warmer temperatures late last week gave farmers a chance to begin seeding fields in the central Corn Belt, according to analysts and government data on Monday.
Three percent of the U.S. corn crop was planted as of Sunday, in line with analysts' expectations ranging from 1 to 5 percent but below the five-year average pace of 6 percent, the U.S. Agriculture Department said in its first such plantings update of 2014.
"Most participants are not too worried given up to a third of the crop can be seeded in just one week (if conditions are favourable)," analyst Luke Mathews of Commonwealth Bank of Australia said.
(Additional reporting by Naveen Thukral in Singapore; Editing by Anthony Barker)