SYDNEY, Dec 14 (Reuters) - U.S. wheat futures rose almost 1% on Monday to a near three-week peak on concerns that key producer Russia would soon move to restrict exports of the grain.

FUNDAMENTALS

* The most active wheat futures on the Chicago Board Of Trade were up 0.7% at $6.18-1/2 a bushel by 0238 GMT, near the session peak of $63.22 a bushel - the highest since Nov 25. Wheat gained 3% on Friday.

* The most active soybean futures were up 0.9% at $11.70-3/4 a bushel, having firmed 0.7% on Friday.

* The most active corn futures were up 1.1% at $4.29 a bushel, having gained 0.5% in the previous session.

* Russian officials are considering imposing a wheat export tax of for Feb. 15-June 30 as one measure to stabilise domestic prices, four sources familiar with discussions told Reuters on Friday.

* Russia's Sovecon agriculture consultancy downgraded its 2021 wheat crop forecast on Friday, citing the worst crop conditions in a decade.

MARKET NEWS

* The British pound rose against the dollar and euro on hopes that Britain and the European Union will secure a free trade agreement after their decision to extend negotiations beyond the Sunday deadline.

* Oil prices rose on Monday, pushing Brent back above $50 a barrel, buoyed by hopes that a rollout of coronavirus vaccines will lift global fuel demand, while an extension of Brexit talks eased jitters on that front for now.

* Stocks started a busy week with guarded gains as investors gauged the chance of added U.S. fiscal and monetary stimulus, while the British pound rose in relief as a last-gasp extension to Brexit talks dodged a hard divorce.

(Reporting by Colin Packham; Editing by Aditya Soni)