South Africa will export 4 million tonnes of surplus maize to the world's biggest emerging markets but wants to ensure security of food supplies in southern Africa first, a minister said on Tuesday.

Africa's top maize producer has been struggling to find markets for a grain surplus after a bumper crop of 12.815 million tonnes in the 2009/10 season, its biggest yield in three decades.

We have positive responses for the exportation of our surplus maize, Tina Joemat-Pettersson, minister of agriculture, told reporters.

The markets that we have developed fall within the ambit of the BRIC countries (Brazil, Russia, India, China) ... (and) we are convinced that we will be able to export our surplus, she added.

In the past week, India's finance minister has said that South Africa had become a member of the BRIC group. China has invited South Africa to join a summit of BRIC leaders this year in Beijing.

South Africa is hoping its new status among the biggest developing countries with some of the world's fastest growth rates will significantly improve its trade and economic relations.

Joemat-Pettersson said discussions on exporting the grain surplus were centred around the logistics, such as harbour control and that she felt the price being asked was correct.

Our price is correct, our price is below the international price. Ours is to ensure as government that we get the best price for our farmers, she said.

Joemat-Pettersson said food security for the country and the southern African region was paramount.

The negotiations that we have with the BRIC countries in particular would be to ensure food security in South Africa, food security in SADC ... before we export the maize, she said.

A senior agriculture official told Reuters in January that South Africa expected to sign a deal with buyers in Saudi Arabia and India for about 100,000 tonnes of its maize surplus.