By Heather Schlitz
CHICAGO, March 27 (Reuters) - Chicago soybean futures ticked lower on profit taking ahead of an expected White House announcement later on Friday of revised U.S. biofuel targets that is expected to be bullish for soybeans, which are often used as a biofuel feedstock.
Wheat and corn were choppy due to uncertainty over the Iran war, with corn also pressured by pre-weekend technical selling.
The most-active soybean contract on the Chicago Board of Trade Sv1 lost 9 cents to $11.64-3/4 a bushel as of 10:50 a.m. CT (1750 GMT).
"We're a little weaker on beans, and it's probably profit-taking before the weekend and headline risk depending on what's happening with Iran and how negotiations are going," said Randy Place, analyst at Hightower Report.
Investors have reacted cautiously to U.S. President Donald Trump's latest comments on talks to end the month-old conflict.
Trump said on Thursday that talks to end the war were going "very well" and that he would delay threatened attacks on Iran's energy plants for another 10 days.
Oil prices LCOc1 turned higher on Friday as traders set Trump's comments against Iran's criticism of the U.S. proposals and ongoing disruption to energy markets. O/R
Grain and oilseed prices have broadly tracked fluctuations in crude oil during the conflict, reflecting the use of corn and soyoil in biofuels and knock-on effects on crop production from rising energy and fertiliser prices.
CBOT corn Cv1 was down 2-3/4 cents to $4.64 a bushel, as grain participants adjust positions before Tuesday's U.S. Department of Agriculture's acreage estimates.
Rising costs of fertilizer resulting from the war in the Middle East could shift acreage from corn to soybeans. Corn requires a substantial amount of nitrogen from fertilizer.
CBOT wheat Wv1 was last down 1/2 cent to $6.04-1/2 a bushel.
Dry conditions affecting part of the U.S. wheat belt have lent support to prices. Traders are closely monitoring drought in the southern U.S. Plains, with hot weather this week raising the risk of more crop stress before possible rain from next week.
The parched conditions are primarily affecting hard red winter wheat production areas, supporting sharper gains this week for Kansas wheat futures KWv1 compared with Chicago prices.