By Jacob Bunge

CHICAGO--Prices of U.S. grain futures managed slight gains in the final trading session of 2016, reflecting a weaker U.S. dollar and promising signs for exports. Soybean prices declined.

Chicago-listed wheat futures on Friday closed 0.8% higher, gaining momentum after the U.S. Department of Agriculture released export sales data that topped analysts' expectations, another promising sign for a U.S. agricultural commodity that has struggled for traction on international markets this year.

Also helping wheat futures was a 0.2% decline in the value of the U.S. dollar versus a basket of international currencies tracked by the WSJ Dollar Index. The U.S. dollar's strength over the past year has made it tougher for grain merchants to market U.S.-produced wheat amid competition from countries with weaker currencies that can make those nations' grain more competitive.

Friday's price moves came at the end of a quiet week in grain markets, with trading volumes muted between the U.S. holidays and with little fresh data to provide direction for contract prices.

Joe Vaclavik, president of Chicago-based Standard Grain Inc., said the number of open positions in Chicago Board of Trade-listed grain futures has declined over the past two weeks as major market participants scaled back their exposure ahead of the New Year. "A lot of people are waiting until after the first of the year to make their decisions," Mr. Vaclavik said.

Positioning by grain traders, farmers and fund managers is expected to pick up ahead of a widely anticipated USDA report scheduled for Jan. 12, which will detail grain stockpiles, final production figures for 2016's harvest and a read on demand, all of which will help to guide farmers' planting strategy for the coming year.

Farmers' key aim this year is to avoid losing money, which has become a tougher task over the past three years as back-to-back bumper crops in North America swelled global supplies. That has pushed down the prices farmers receive when they sell their crops to grain elevators, which funnel them to food processors, livestock operations and overseas buyers.

Chicago wheat futures, which settled 3 1/4 cents higher at $4.08 a bushel for March-dated contracts Friday, have declined 13.2% for the year. As wheat's price has tumbled, U.S. exports and plantings have fallen to their lowest levels in decades.

March corn futures closed slightly higher on Friday, climbing 0.6% to $3.52 a bushel. Corn futures, which ended the year 2% lower than where they started, spent much of 2016 trading between $3.50 and $4.00 a bushel. At those levels, many farmers struggled to turn a profit, despite planting more of the grain in hopes that they would be able to make up for low prices with high yields.

Soybean futures expiring in January settled 0.7% lower at $9.96 1/2 a bushel, as traders balanced export sales data that generally fell in line with expectations against continued concerns over dryness in stretches of northern Brazil that could spell trouble for soybean yields there.

Soybeans, which are expected to find more favor among U.S. farmers as planting gets underway in the months ahead, climbed 14% this year, thanks to tighter supplies and robust demand among processors and animal-feed makers.

-Write to Jacob Bunge at jacob.bunge@wsj.com

(END) Dow Jones Newswires

December 30, 2016 15:01 ET (20:01 GMT)

Copyright (c) 2016 Dow Jones & Company, Inc.