Local media attributed these shortages, also seen for some dairy products, partly to heavy demand and recent flooding in northern Argentina.

But a trip to supermarkets in Buenos Aires tells another story. A branch of Jumbo, a super market chain owned by Chile's Cencosud SA in Buenos Aires' Palermo neighborhood, put out placards this week apologizing to its clients for the shortage of some beef cuts, blaming a lack of supply at the prices suggested by government price controllers.

Meanwhile, the meat counter at a locally owned Coto supermarket chain store in the Barrio Norte district had a similar tale and sign blaming price accords.

Coto was also missing some dairy products, a clerk said. "There's plenty of expensive milk, but you can't find the cheap price-accord milk anywhere," said Patricia Umanski, an Argentine shopper, as she returned from a Coto in the Bella Vista suburb.

The government has sought to impose maximum prices on twelve of the most popular beef cuts at Liniers, Buenos Aires' principal wholesale meat market.

As a result, volume passing through Liniers has plunged to less than half of normal levels as ranchers instead send cattle to smaller regional markets not under the federal government's price surveillance.

The attempt to control prices is spurring the development of two parallel markets - one with high prices and ample stocks, the other with low prices and empty shelves.

"There isn't any more beef available at the official reference prices," said a butcher at an independent market in the Buenos Aires suburb of Martinez. Wholesale prices have surged 15% over the past month, he added.

At Coto Supermarkets, where shortages are acute, a popular rib cut is quoted at 8.59 Argentine Pesos ($3 dollar) per kilo. The small butcher in Martinez has plenty of the ribs to offer - but at 16 pesos per kilo.

Fears Of A Black Market

"The shortage of products is a clear signal of a market distortion resulting from the government-imposed price controls," said Esteban Fernandez Medrano, director of MacroVision, a local economic consultancy. Argentina's past experiences with price controls in the 70s and 80s led to the emergence of a black market for missing products, he said, noting that price controls aren't sustainable in the long-term.

"We have to see how long these shortages last," Medrano said. Indeed, not all supermarkets are struggling to stock shelves. Norte, a supermarket chain controlled by French retailing giant Carrefour SA, isn't suffering beef shortages.

"Our beef sales went up by 40% in the last fifteen days" since competitors started running out of products, said Carlos Marasco, who manages the meat section at Norte's store in Barrio Norte.

Beef consumption in Argentina is the highest in the world, with per-capita consumption at about 65 kilograms per year. Beef prices are so important to Argentine consumers that they make up 7% of the consumer price index.

That's why increased prices pose a major challenge to the government of President Nestor Kirchner ahead of presidential elections due in October.

In its effort to control prices, the government has intervened heavily also on beef exports, which are currently limited to about 70% of year-earlier levels. Despite this, local prices have continued to surge due to increasing international and domestic demand amid tight supply.

There is now widespread evidence of a sharp decline in cattle-raising as farmers - squeezed by rising prices of diesel, land and labor - turn to more profitable products, such as soy, corn and other cereals.

"Farmers are going more and more for the product that gives them the most security, which is soy," said the President of the Rosario Grain Exchange, Jorge Weskamp.

This trend will threaten Argentina's position as the world's third-largest beef exporter after Brazil and Australia. Furthermore, analysts say, it has left no buffer room for boosting supply at times of need and any outside shock to production or distribution, such as the recent storms, easily gives rise to a spike in prices.

The Secretary of Interior Commerce, Guillermo Moreno, who is in charge of the government's price control policy, wasn't immediately available for a comment.