By Alex Ritson BBC World Service business reporter

Five southern African countries are lobbying hard for a limited resumption of trading in ivory.

The current ban, which was introduced in 1989, was widely credited with slowing an alarming slide in the continent's elephant population - which had halved in a little over a decade.

We would like to sell whatever ivory we accumulate from natural mortalities

Mavuso Msimang, South African negotiator

Now South Africa, Namibia, Botswana, Zimbabwe and Zambia want to be allowed to start selling their stockpiles of elephant tusks.

The battle over a possible return to ivory trading will be fought at a diplomatic level far from Africa.

Delegates are gathering in Santiago in Chile, for the conference of the Convention on International Trade in Endangered Species.

Natural deaths

The leader of the South African team of negotiators, Mavuso Msimang, told the BBC's World Business Report that most of the ivory for sale came from elephants that had died from natural causes.

"We would like to sell whatever ivory we accumulate from natural mortalities," he said.

He added that some of the ivory was from elephants that had been culled - before the practice was stopped in 1996.

He maintained that there would be about two tons of ivory offered for sale each year, on top of the one-off disposal of present stocks.

Rhino has been hunted almost to extinction

But the proposals are a long way from having the support of all countries in Africa.

Kenya is leading the campaign to keep the ban in place.

It fears wild elephants across the continent will be targeted by poachers seeking to "launder" dirty ivory with legal supplies.

Jason Bell-Leask, from the International Fund for Animal Welfare (IFAW), told the BBC's World Business Report that he was sympathetic to South Africa's view.

"They do need resources to be able to fund conservation activities," he said.

Poaching threat

"What we advocate is that the developed world comes to the party to ensure that the financing of elephant protection is funded," he said.

History has shown that demand can never be satisfied through legal sources

Jason Bell-Leask, IFAW

Those in favour of a return to ivory trading insist it would take place only under strictly supervised conditions.

Ivory would be sold only to countries with a system of monitoring to ensure poached ivory was not being sold alongside legal supplies.

Mr Msimang insisted the new system itself would not encourage poaching.

"People trade in rhino horn, which has been banned for a long time," he said.

"Smugglers will always find a market."

Mr Bell-Leask, too, fears that smuggling will continue whatever happens: "History has shown that demand can never be satisfied through legal sources."

He said it could only be satisfied through illegal activities.