CHICAGO, April 19 (Reuters) -

U.S. corn and soybean prices rose on Friday as heightened geopolitical tensions spurred a round of bargain buying after the benchmark contracts in both markets fell to their lowest in more than six weeks, traders said.

Corn futures drew additional support from news that the U.S. Environmental Protection Agency will temporarily

expand sales

of higher-ethanol blends of gasoline this summer.

As of 12:43 p.m. CDT (1743 GMT), Chicago Board of Trade July corn was up 6-3/4 cents at $4.43 per bushel. July soybeans were up 17-1/4 cents at $11.66-1/4 a bushel, rallying after a dip to $11.45-3/4, the contract's lowest since Feb. 29. CBOT July wheat was up 12-1/4 cents at $5.65-1/4 a bushel.

Analysts said traders were squaring positions ahead of the weekend and after recent declines. For the week, July corn was on track to fall 1.1%, while July soybeans were down 1.8% and July wheat was down 0.9%.

Soybean futures were anchored in part by supplies of cooking oil coming into the United States from overseas and depressing the soyoil market, said Don Roose, president of Iowa-based U.S. Commodities. CBOT July soyoil futures hit a contract low in early moves before bouncing.

Corn firmed following an

announcement

by the EPA that it would widen the summertime sales period for higher-ethanol blends of gasoline in an effort to reduce potential supply disruptions amid ongoing conflicts in Ukraine and the Middle East.

The move "is not going to cause a big increase in ethanol demand. Rather, it will avoid a seasonal dip in demand. Its market impact is more psychological," StoneX chief commodities economist Arlan Suderman wrote in a client note.

Reports of Israeli missile strikes in Iran overnight fuelled fears of an escalating conflict in the Middle East, and pushed wheat prices up 4% after the first reports of the strike emerged. Traders had feared that expanding violence in the region could impact shipments in the region and from Russia, the world's biggest wheat exporter and an ally of Iran.

But Tehran played down the incident and indicated it had no plans for retaliation.

Crude oil prices also pared their gains after having surged amid concerns that Middle East oil supply could be disrupted.

(Reporting by Renee Hickman; additional reporting by Peter Hobson in Canberra and Sybille de La Hamaide in Paris, Editing by Louise Heavens)