SINGAPORE, June 26 (Reuters) - Chicago wheat futures lost more ground on Wednesday, with the U.S. winter crop harvest adding pressure on prices amid some rain relief for crops in Russia, the world's top exporter.

Corn slid, while soybeans inched higher as the market assessed the impact of floods on crops in the U.S. Midwest.

FUNDAMENTALS

* The most-active wheat contract on the Chicago Board of Trade (CBOT) was down 0.2% at $5.59-1/4 a bushel, as of 0016 GMT, having hit its weakest since April 19 at $5.56-3/4 a bushel, earlier in the session.

* Corn lost 0.2% to $4.42-1/4 a bushel and soybeans added half a cent to $11.12 a bushel.

* Wheat fell as the U.S. harvest marched ahead, showing good yields. There was additional pressure on wheat as crops stabilized with improved weather in Russia after weeks of droughts and frost.

* More flooding hit parts of the U.S. Midwest on Tuesday after a weekend of thunderstorms caused excess water in some areas.

* Some traders are assuming that moisture from floods will be ultimately beneficial for crops.

* A heatwave due to spread throughout Europe this week is set to take a heavy toll on summer crops in the southeast, but is good news for farmers on the other side of the region after prolonged rains flooded fields and hampered plants' growth, analysts said.

* Commodity funds were net sellers of CBOT corn, wheat, soybeans, soymeal and soyoil futures contracts on Tuesday, traders said.

MARKET NEWS

* Global stock indexes mostly climbed on Tuesday, with shares of AI chipmaker Nvidia bouncing after a three-day sell-off, while the dollar gained slightly against the Japanese yen.

DATA/EVENTS (GMT) 1000 France Unemp Class-A SA May 1400 US New Home Sales-Units May (Reporting by Naveen Thukral; Editing by Sherry Jacob-Phillips)