New York gold futures regained the $US1,500-an-ounce mark on Friday for the first time in a week thanks to those renewed fears about Greece's financial state and differences in Europe over its new rescue.

As well there were worries about those local polls in Spain, and to a lesser extent in Germany.

In Bremen the fear is that The Greens could finish second behind the Social democrats, relegating Chancellor Angela Merkel's CDP to third.

And the metal will get a further kick this week after Italy's credit rating outlook was moved to negative by Standard & Poor's late on Friday, a move that surprised some analysts.

That will be despite the gathering strength of the US dollar, which is rising off those fears about Europe.

The dollar made a small gain against the euro last week of around 0.3% (with all that and more in Friday's 1.1% rise), and yet gold, oil and copper stood out with gains on the day and for part or all of the week.

Comex June delivery gold rose $US16.50, or 1.1%, to $US1,508.90 an ounce in New York on Friday night.

That was the metal's first settlement above $1,500 since May 12, and the highest for a most-active gold contract since May 10.

Gold finished the week up 1%.

Comex July silver also settled higher, gaining 16 cents, or 0.4%, to $35.09 an ounce.

Silver was also up for the week with a rise of 0.3%.

The dollar index, which tracks the U.S. unit against a basket of six currencies, stood at 75.444 at the close Friday night, up from 75.106 in late Thursday.

Friday's gains for gold and silver came after falls on Thursday.

US bond yields fell Friday to 3.1%, down 0.02% on the day.

Other metals shook off weak starts to post gains on Friday.

Comex July copper rose 7 cents, or 1.7%, to $US4.12 a pound, a partial reverse of Thursday's 5c a pound fall.

Over the week copper added 3.5%, one of its biggest rises of late.

Crude-oil futures traded higher Friday, closing in on the $US100 a barrel mark.

The expiring US June crude contract rose $US1.05 to go off the board (finish trading) at $US99.49 a barrel, after falling as low as $US95.99.

Despite the rally it ended the week down 16 cents.

The US July crude rose $US1.17 to settle at $US100.10, bouncing from its intraday low of $US96.35.

In London, Brent crude for July delivery rose 97 cents to settle at $US112.39 a barrel, bouncing off a low of $US108.60 posted after sliding below the 100-day moving average of $US109.76.

For the week, front-month Brent fell $US1.44, or 1.27%.

Reuters said that like Wall Street, trading volumes in oil are low at the moment.

And watch the markets for big moves in coming weeks for corn, rice and corn and soybeans.

That heavy rain and flooding in the US Midwest and south looks like continuing, three of China's main rice growing areas are facing an expanding drought that is already impacting yields and growing. This is after drought hit the wheat and soybean crops.

And France is suffering under drought with 42 of the country's 92 mainland departments imposing water use bans or restrictions.

And the dry weather is hurting parts of Germany and the US as well.

Bloomberg reported that Chicago Board of Trade corn futures for July delivery rose 11.25 US cents, or 1.5%, to settle at $US7.595 a bushel on Friday.

Prices jumped 11% last week, the biggest weekly rise since last October.

Chicago soybean futures for July delivery rose 0.75% to settle at $US13.8025 a bushel. Prices rose 3.8% last week, the biggest gain in nearly five months.

And Chicago wheat prices fell 0.7% on Friday to $US8.065 a bushel

That left pries with an 11% gain last week, the biggest jump for six months.