G20 farm ministers wrangled over France's proposals to tighten regulation of commodity markets and set up emergency reserves at a summit on Wednesday as the group seeks to tackle soaring and volatile food prices.

Paris has made tougher commodity trading rules a priority of its 2011 presidency of the Group of 20 leading economies as President Nicolas Sarkozy has blamed speculators for food price inflation that fed unrest in North Africa and the Middle East.

"I prefer to take responsibility for a failure rather than a half-hearted agreement or an agreement for appearance's sake," French Agricultre Minister Bruno Le Maire told French radio Europe 1.

He warned that a failure to adopt concrete measures to tame surging staple food prices before the summit concludes on Thursday could give way to more riots.

A draft communique obtained by Reuters last week showed the farm ministers could end up with a watered-down deal limiting decisions to agricultural issues, mainly data or food supplies, not markets.

"The (G20) goal has been set by the president to prevent the 21st century from becoming the century of hunger," Le Maire told French daily Le Parisien on Wednesday.

Surging demand for food and fuel will keep commodities under pressure this decade, international bodies warned last week, saying this trend would be marked by fresh bouts of volatility that could hurt producers and consumers.

Benchmark international wheat prices are up about 50 percent in the past 12 months alone, while corn prices have doubled.

While all G20 nations have agreed that steps must be taken to tackle surging food prices, they are split over whether prices should be tamed by regulation or by increased agricultural production and productivity. BOOST OUTPUT

"Argentina will emphasize the importance of stimulating production growth rather than controlling it, in contrast to the French proposal to regulate financial markets linked to raw materials," Argentine Agricultural Minister Julian Dominguez said on Tuesday.

Britain, Europe's financial markets hub, has also said it saw little value in more regulation, but the Russian agriculture ministry told Reuters that Moscow was "ready to give full support to the elaboration of a mechanism of financial regulation and control of the agricultural markets". A source close to the French negotiations said on Tuesday that Le Maire was in back-to-back telephone calls to G20 peers to clinch a deal that also includes proposals to improve market transparency and global policy coordination and set up humanitarian food stocks.

"This is tough. Until the end there is no certainty of an agreement," said the source about a deal that would be a boon for Sarkozy who is seeking to impress on the world stage ahead of what is expected to be a tough re-election battle in 2012.

"I hope we will have an agreement. Bruno Le Maire is doing everything he can to get one," the source added.

The draft communique mainly covers purely agricultural issues such as the launch of a database on national farm supplies, a joint research programme on wheat and a rapid response forum between G20 states in case of a food crisis.
G20 ministers would also agree to set up food aid reserves and remove export restrictions for humanitarian supplies. But there may be resistance even on these points as China is reluctant to share information it sees as strategic. China also considers, as does India, that giving exhaustive and timely data on stocks would be difficult for practical reasons.