The bank reduced its estimate for returns to 12 percent from 15 percent after prices rallied this year, analysts led by Jeffrey Currie said in a report today. They kept their predictions for Brent and gold at $127.50 a barrel and $1,940 an ounce compared with $121.54 and $1,756.50 today.

Commodities advanced 8.5 percent this year to the highest level in six months as measured by the Standard & Poor’s GSCI index of 24 raw materials. Prices climbed as the U.S. economy strengthened and the Chinese central bank cut reserve requirements. While Morgan Stanley is also bullish on gold, it expects oil prices to decline in the first half as supply recovers and demand slows, it said in a report Feb. 20.

“With much of the ‘value’ opportunities behind us, we look to fundamental drivers for further expected gains in 2012, which we believe will be centered in the oil complex,” said Goldman. Oil climbed to a nine-month high in New York yesterday after Greece won a second bailout. Gold advanced 12 percent this year.

The bank is bullish on oil because the price is vulnerable to supply disruptions from Iran and elsewhere and OPEC spare capacity is “at a trough” just as the world economic recovery is gaining momentum, it said.

Iran, China

The European Union agreed last month to ban crude imports from Iran starting July 1 to increase pressure on the country over its nuclear program. The Middle Eastern country said Feb. 19 it stopped selling crude to France and Britain.

Brent for April delivery fell 0.1 percent to $121.54 in London today and gold for the same month in New York also declined 0.1 percent to $1,756.50 an ounce.

Manufacturing in China, the biggest consumer of energy and industrial metals, may shrink for a fourth month in February, indicating the economy remains vulnerable to a deeper slowdown as Europe’s crisis caps exports and the home market cools.

The preliminary 49.7 reading of an index from HSBC Holdings Plc and Markit Economics today compared with a final 48.8 in January. A number below 50 signals a contraction. January and February economic data are distorted by a weeklong holiday.

“Chinese construction activity and consumer appliance output remain relatively weak,” the Goldman analysts said. “Recent fundamental developments leave us happy to stay on the sidelines” of industrial metals for now, it said.

The bank predicts copper and aluminum at $9,000 a ton and $2,400 a ton in 12 months compared with $8,430 and $2,252 now.

The analysts see “little outright opportunity” in agriculture, predicting lower prices in wheat and corn in 12 months and a 1 percent gain in soybeans.