Oil increased this week as gasoline jumped to the highest level since August and on signs Greece is near an agreement with its creditors.

Futures were little changed after gasoline rose on speculation that refinery outages and plant closures will cut supplies. Olli Rehn, the European Union’s commissioner for economic and monetary affairs, said an agreement is “very close” on private-sector involvement in a Greek debt swap.

“The closing of a number of refineries in the Northeast is making people very supply-conscious during a period with weak gasoline demand,” said Peter Beutel, president of trading advisory company Cameronhanover.com in New Canaan, Connecticut. “Expectations that they will put together a Greek deal soon are lifting the entire complex.”

What follows are opening calls for U.S. grain and oilseed markets.

-- Corn futures are called to open 3 cents to 5 cents a bushel higher on the Chicago Board of Trade on speculation that adverse weather this month reduced output in South America, Don Roose, the president of U.S. Commodities Inc. in West Des Moines, Iowa, said in telephone interview. Farmers withheld inventories, boosting premiums that grain companies are paying to acquire prompt supplies.

European Union sanctions on Iranian oil will extend to about 95 percent of tankers because they are insured under rules governed by European law.

The International Group of P&I Clubs insures all but 5 percent of the global tanker fleet and its 13 member clubs follow European rules to participate in the claim-sharing pool, said Andrew Bardot, the London-based secretary and executive officer. Carrying Iranian oil would invalidate the ships’ cover against risks including spills and collisions, he said.

Corn advanced, heading for the biggest weekly gain in five, as concerns that a renewed heat wave in Argentina may damage crops boosted demand for U.S. grain. Soybeans were little changed.

The weather pattern known as La Nina has brought hot, dry conditions to Argentina, Brazil and Mexico, scorching recently planted crops. Temperatures will exceed 40 degrees Celsius (104 degrees Fahrenheit) in some of Argentina’s corn-growing areas through Feb. 2, the Buenos Aires Cereals Exchange said yesterday. Rain will be scarce in most areas, said climatologist Eduardo Sierra.

Gold traders are bullish for a fourth consecutive week, betting that the Federal Reserve’s pledge to keep interest rates low until late 2014 will extend the metal’s best start to a year in more than three decades.

Nine of 15 surveyed by Bloomberg expect prices to gain next week. The value of gold held in exchange-traded products jumped $3.9 billion on Jan. 25, the most since October, as the central bank laid the groundwork for a possible third round of asset purchases, data compiled by Bloomberg show. Lower interest rates increase the appeal of bullion because it generally earns investors returns only through price gains.

Oil headed for its first weekly gain in three, trading near a one-week high in New York amid signs of economic recovery in the U.S., the world’s biggest crude consumer.

Futures gained as much as 0.8 percent, advancing for a third day. The U.S. Commerce Department may say today that economic growth accelerated in the fourth quarter. Durable goods orders rose more than forecast in December, according to data published yesterday, and a report this week showed gasoline demand grew the most in more than two months. Total SA Chief Executive Officer Christophe de Margerie said it would take a “real recession” to send Brent crude below $100 a barrel.

Corn advanced, heading for the biggest gain in five weeks, as concerns that a renewed heat wave in Argentina may damage crops boosted demand for U.S. grain. Soybeans gained.

The weather pattern known as La Nina has brought hot, dry conditions to Argentina, Brazil and Mexico, scorching recently planted crops. Temperatures will exceed 40 degrees Celsius (104 degrees Fahrenheit) in some of Argentina’s corn-growing areas through Feb. 2, the Buenos Aires Cereals Exchange said yesterday. Rain will be scarce in most areas, said climatologist Eduardo Sierra.