* Corn prices shrugged off earlier losses to turn higher, gaining 3.5 percent for the week for the best weekly performance since June. Most-active CBOT December corn has not declined since reaching a life-of-contract low of $3.14-3/4 per bushel on Aug. 31.
* The gains came ahead of a monthly supply and demand report, in which the government was expected to trim the average corn yield to 173.4 bushels per acre, down from 175.1 bpa on Aug. 12, but still a record high, according to a Reuters analyst poll.
* USDA earlier said corn export sales for the week ended Sept. 1 totaled 1,093,300 tonnes for 2016/17 and 30,500 tonnes for 2017/18. USDA said 3,430,100 tonnes in sales were carried over from the 2015/2016 marketing year, which ended Aug. 31.
* Forty-six deliveries were posted against CBOT September corn futures, which expires next week.