RIYADH: Gold prices treaded water on Wednesday, with lower US Treasury yields lending support, as bullion struggled to break out of range-bound trading. Spot gold was up 0.1 percent at $1,821.53 per ounce by 0550 GMT. US gold futures firmed 0.1 percent at $1,822.10. Silver dips Spot silver dipped 0.1 percent to $20.81 per ounce, while platinum rose 0.9 percent to $918.32. Palladium gained 2 percent to $1,911.72. Wheat up, corn down Chicago wheat futures extended gains on Wednesday, lifted by signs of improving demand and bargain-buying after three straight sessions of losses pushed the contract to its lowest since February. Corn and soybeans edged lower. The most active wheat contract on the Chicago Board of Trade rose 0.53 percent to $9.41 a bushel. Corn fell 0.38 percent to $6.56-3/4 a bushel and soybeans edged down 0.5 percent to $14.55-1/4 a bushel. Copper down Copper prices slipped on Wednesday, as downbeat US consumer confidence data and prospects of rapid rate hikes to control a surge in inflation fanned fears of a global economic slowdown, impacting metals demand. Three-month copper on the London Metal Exchange was down 0.6 percent at $8,314 a ton, as of 0702 GMT. Prices of the metal, which are used as a gauge of economic health by investors, have fallen 23 percent since scaling a peak of $10,845 in March. The most-traded August copper contract in Shanghai ended daytime trading down 0.9 percent to $9,466.07 a ton. (With inputs from Reuters)