CHICAGO, April 29 (Reuters) - Spot basis bids for corn were mixed while soybean basis bids were flat in the U.S. Midwest on Tuesday as selling remained slow and farmers remained focused on ongoing fieldwork, dealers said.

• Spot corn basis bids rose at an Ohio elevator and an Iowa ethanol plant and decreased at an Illinois ethanol plant.

• Soy basis bids were steady.

• Chicago corn and soybean futures turned lower on Tuesday amid ongoing planting and a lack of fresh news over the U.S.-China trade war.

• Corn and soybean markets also were pressured from favorable crop weather in South America. Recent showers have eased drought conditions that threatened Brazil's safrinha corn crop, while a dry spell in Argentina is set to help corn and soybean harvesting after heavy rain.

• The USDA said 24% of the nation's corn crop and 18% of soybeans were planted as of Sunday. Analysts had estimated 25% of corn and 17% of soybeans were planted, according to a Reuters poll.

• Elevators and processors are beginning to roll their basis bids to July futures contracts from May futures ahead of the upcoming delivery period for May contracts.

• Chicago Board of Trade soybean futures Sv1 were last down 15 cents to $10.47-1/2 per bushel as of midday.

• CBOT May corn CK25 was last down 11-1/4 cents to $4.72 a bushel.

Basis values are quoted against CBOT futures in cts/bu:

NOTE: 0 = Option price, UNC = Unchanged, UNQ = Unquoted

NC = Not comparable, DP = Delayed price, N/A = Not available,

F = January, H = March, K = May, N = JulyQ = August, U = September, X = November, Z = December

--------------------------------------------------------

LINKS: 0#USCSHGRN-PM

For U.S. forward basis spreadsheets, please click:

CORN/BASIS, SOYA/BASIS, WHEAT/BASIS, MILO/BASIS

- CBOT corn report COR/

- CBOT soybean report SOY/C

- CBOT wheat report WHE/C

- U.S. grain barge freight values BG/US

- U.S. Midwest cash grain PM GRA/PM

- U.S. CIF/FOB Gulf Grain GRA/F

(Reporting by Heather Schlitz; Editing by Richard Chang)

((Heather.Schlitz@tr.com))