NEW YORK — Corn prices jumped to a record $6 a bushel Thursday, driven up by an expected supply shortfall that will only add to Americans' growing grocery bill and further squeeze struggling ethanol producers.

Corn prices have shot up nearly 30 percent this year amid dwindling stockpiles and surging demand for the grain used to feed livestock and make alternative fuels including ethanol. Prices are poised to go even higher after the U.S. government this week predicted that American farmers — the world's biggest corn producers — will plant sharply less of the crop in 2008 compared to last year.

"It's a demand-driven market and we may not be planting enough acres to supply demand, so that adds to the bullishness of corn," said Elaine Kub, a grains analyst with DTN in Omaha, Neb.

Corn for the most actively traded May contract rose 4.25 cents to settle at $6 a bushel on the Chicago Board of Trade, after earlier rising to $6.025 a bushel — a new high.

Worldwide demand for corn to feed livestock and to make biofuel is putting enormous pressure on global supply. And with the U.S. expected to plant less corn, the supply shortage will only worsen. The U.S. Department of Agriculture projected that farmers will plant 86 million acres of corn in 2008, an 8 percent drop from last year.

Moreover, cold, wet weather in parts of the U.S. Corn Belt may force farmers to delay spring planting, potentially sending prices even higher.

While corn growers are reaping record profits, U.S. consumers can expect even higher grocery bills — especially for meat and pork — as livestock producers are forced to pass on higher animal feed costs and thin their herd size.

"Higher corn prices (are) going to affect meat prices. If you're feeding with $6 corn, you'll definitely have some (cost) pressure," Kub said.

Key ingredient in other items

In addition, corn and corn syrup are used in an array of products, meaning the price of everything from candy to soft drinks eventually will go up, analysts say. It's the latest dose of bad news for U.S. consumers, who are already struggling with higher food costs from record increases in the prices of wheat, soybeans and other agriculture products.

Another loser in higher corn costs is ethanol producers, who are struggling to squeeze out gains as corn's record-setting run outpaces the price of ethanol, currently at about $2.50 a gallon.

"For years, corn was cheap and fermentation processes for ethanol production came to completely dominate the biofuel industry in North America," Michael Jackson, president and chairman of Vancouver-based ethanol maker Syntec Biofuel, said this week. "Now, with corn prices well over $5 a bushel, corn ethanol economics have gone out the window."

The nation's 147 ethanol plants now have the capacity to produce 8.5 billion gallons of fuel a year, according to the Renewable Fuels Association. Corn is the basic feedstock for most of the plants and about 20 percent of last year's 13 billion bushel corn crop was consumed by ethanol production. That percentage is expected to increase to 30 percent for the next crop year, which will end Aug. 31, 2009, according to Terry Francl, a senior economist for the American Farm Bureau Federation.

Some plans put on hold

There are still plans to build or expand an additional 61 plants, which will add about 5.1 billion gallons of capacity. However, as corn prices have climbed over the past year or so, construction of several plants has been halted or delayed, shaving about 500 million gallons worth of capacity off the original figure, according to Broadpoint Capital analyst Ron Oster.

At least one facility, the Alchem plant in Grafton, N.D., shut down late last year because of high prices.

A new plant hasn't broken ground over the past couple of quarters, Oster said, and while producers can have positive gross margins with ethanol at $2.50 a gallon and corn at $6 a bushel, that doesn't mean companies are profitable.

"Bottom-line earnings are near break-even or modestly below break-even," he said.

Looking ahead, only the strongest ethanol producers will survive in an era of ever-rising corn prices, said Soleil Securities analyst Ian Horowitz.

"There are going to be some particular companies that definitely have the balance sheet and efficiencies that will be able to eke out a positive return in this kind of environment," he said, "and then there will be others that will suffer at the hands of $6 corn."