Rich nations buying farmland in less developed countries to boost own food supplies should also contribute to improving agriculture overseas, heads of two UN food agencies said.

Food supply scare after last year's food riots has pushed several countries, such as China, Saudi Arabia and South Korea, to buy or lease farmland overseas to feed their own people. Quickly nicknamed "land-grabbing," this phenomenon has drawn sharp criticism for ignoring interests of local population. A leader of major international farmer group, IFAP, has said there was a risk of "second-generation colonialism" in such deals.

But heads of the UN agencies, Food and Agriculture Organisation and International Fund for Agricultural Development said cross-border farmland deals can be mutually beneficial and help boost global food security.

"I would not call it "land-grabbing" ... There is a potential for win-win situations there," IFAD President Kanayo F. Nwanze said in an interview at the first meeting of farm ministers from the Group of Eight countries.

Mr Nwanza said there was a risk of depriving poor farmers from access to farmland in their own countries when foreign investors move in.

But when such deals take into account interests of both parties they help increase agricultural production in developing countries, provide jobs, boost export and bring in new technologies to improve farm efficiency there, added Mr Nwanze.

Private investment in developing agriculture in poorer countries is urgently needed if the world wants to double food output by 2050 and stamp out hunger which affects about one billion people, FAO's Director-General Jacques Diouf said.

Mr Diouf told Reuters joint ventures could be the way to ensure a balance between the interests of investors and recipient countries.

But Germany's Agriculture and Consumer Protection Minister Ilse Aigner struck a cautious note.

"We're a bit careful on that. We believe that every country should own their land to make sure they can feed their own people," she said.

Both Mr Diouf and Mr Nwanze called on the G8 farm ministers to come up with concrete measures to boost investment in agriculture in developing countries where there is an urgent need to boost fertilizer use, improve irrigation and infrastructure.