(Updates U.S. market activity to close)
CHICAGO, Jan 23 (Reuters) - U.S. grain futures were lower on Tuesday, with wheat dropping about 1 percent and corn easing for the second straight session on chart-based selling and abundant global stockpiles, traders said.
Soybeans edged slightly higher, gaining for the seventh straight session to the highest in about six weeks. Warm and dry conditions stressed the developing crop in Argentina, the No. 3 soy producer after the United States and Brazil, prompting buying.
There was little fresh news to alter momentum for any of the crops, and investment funds still had sizeable net shorts in each. Rain mixed with snow fell in parts of wheat-growing areas in the U.S. Midwest, providing moisture to the dormant soft red winter wheat crop.
CBOT SRW wheat futures for March delivery fell 4-1/4 cents to $4.21-1/2 per bushel while K.C. March hard red winter wheat shed 5-1/4 cents to $4.23-1/4, both the lowest in about a week.
"Everyone is marking time until wheat breaks dormancy," said INTL FCStone analyst Arlan Suderman.
MGEX March spring wheat was down 2-1/2 cents to $6.04-1/2 per bushel, touching the lowest levels since June.
CBOT March corn finished 3/4 cent lower at $3.51-1/4 per bushel, trimming declines late in the session.
CBOT March soybeans were up 2 cents at $9.86-1/4, weakening after an earlier high of $9.88-3/4.
Commodity funds were net sellers in wheat and corn and net buyers in the CBOT soy complex, traders said.
Analytics firm Informa Economics trimmed its forecasts for 2018 U.S. soybean and corn plantings, even as their outlook for 91.387 million soybean acres still would be the most ever.
Argentine soy and corn farmers are facing yield losses this season due to hot, dry weather that persisted over the weekend and was expected to continue in the days ahead, a Buenos Aires Grains Exchange weather consultant said on Monday.
Argentina is not in an actual drought but conditions are not optimal for crops, said consultant Eduardo Sierra. (Additional reporting by Michael Hogan in Hamburg and Naveen Thukral in Singapore; Editing by James Dalgleish)