Chicago soybeans extended gains to one-week highs on Friday, as higher than expected U.S. export sales and the prospect of post-holiday demand in China boosted demand prospects.

Gains were limited by a slight recovery in the dollar and ample global supplies that continued provide a bearish backdrop to grain and oilseed markets, however.

Wheat edged higher as it recovered further from this week's 5-1/2 year low, while corn was almost unchanged as it consolidated after hitting a three-week trough earlier in the week.

The U.S. Department of Agriculture on Thursday reported weekly soybean export sales of 666,800 tonnes, above the high end of trade expectations ranging from 300,000 to 600,000 tonnes.

"The soybeans exports market is getting active. Chinese importers are going to be back next week," Kaname Gokon at the Okato Shoji brokerage in Tokyo said. "But Brazil and Argentina have large supplies, which will prevent the market from rallying."

Markets in China, the world's biggest soybean importer, have been closed this week for the Lunar New Year holiday.

The Chicago Board Of Trade most-active soybean contract was up a quarter of a cent at $8.73-3/4 by 1159 GMT, after earlier reaching its highest since Feb. 5 at $8.75-1/2 a bushel.

CBOT corn inched down 0.1 percent to $3.59-3/4, after rising on Thursday to end a six-session falling streak. Wheat was up 0.6 percent at $4.60-3/4 a bushel, as it steadied above Tuesday's low of $4.55, its weakest since late June 2010.

Corn has been facing pressure from tepid exports and the risk of slowing demand for corn-based ethanol.

The USDA reported weekly net export corn sales of 405,000 tonnes, well below forecasts for 800,000 to 1.1 million tonnes.

A sharp rally in crude oil on Friday lent some support to crops such as corn which are used in biofuels.

Wheat traders were awaiting the outcome of a tender by Egypt, the world's biggest buyer of the food staple, to see if a standoff over import terms was any nearer resolution.

Traders reported a limited number of offers in the ongoing tender, suggesting suppliers remained wary of Egypt after confusion over its policy on grain fungus ergot.

Earlier this week, the USDA pegged end-year wheat stocks at above trade expectations, largely due to a 4 million tonne cut in usage by China, reflecting that country's policy shift that favors other grains.