CBOT Trends-Wheat up 4-7 cents, corn up 2-4, soybeans up 7-9

CHICAGO, May 21 (Reuters) - The following are U.S. expectations for the resumption of grain and soy complex trading at the Chicago Board of Trade at 8:30 a.m. CDT (1330 GMT) on Wednesday.

WHEAT - Up 4 to 7 cents per bushel

• CBOT wheat futures higher for a third straight day on short-covering and technical buying. Rising concerns about global crops adding support.

• Actively traded CBOT July wheat WN25 was up for the sixth time in seven sessions and touched a one-month high after breaking through technical resistance at its 50-day moving average during overnight trading.

• High temperatures and a lack of rain over the coming months are expected to deplete the harvest in Russia's largest grain region Rostov, the head of the local grain lobby group said.

• Argentina will extend a tax break on exports of wheat, Economy Minister Luis Caputo said on Tuesday.

• CBOT July soft red winter wheat WN25 was last up 6 cents at $5.52 per bushel. K.C. July hard red winter wheat KWN25 was last up 6-1/4 cents at $5.42-1/2 a bushel. Minneapolis July spring wheat MWEN25 was last up 6 cents at $6.03-1/4 a bushel.

CORN - Up 2 to 4 cents per bushel

• Corn futures firm on short-covering as rains across much of the Midwest delayed planting and stoked concerns that total acreage could decline. But gains were limited as rains were seen boosting already planted crops.

• Algerian state agency ONAB issued a new tender to purchase up to 80,000 metric tons of optional-origin animal feed corn.

• CBOT July corn CN25 was last up 2-1/2 cents at $4.57 per bushel.

SOYBEANS - Up 7 to 9 cents per bushel

• Soybeans higher on U.S. Midwest planting delays and concerns about rain-damaged crops in Argentina. But U.S. Midwest rains seen benefiting already planted soy, limiting market gains.

• CBOT July soybeans SN25 were last up 7-1/4 cents at $10.60-1/4 per bushel.