By MacDonald Dzirutwe

HARARE (Reuters) - Zimbabwe could quadruple its cotton output to 1 million tonnes by 2015 -- if it starts to grow genetically modified crops and increases support to farmers, an official with agro-industrial firm Aico Africa Ltd said on Thursday.

Pat Devenish, chief executive of Aico Africa, Zimbabwe's largest producer of cotton lint and seed, said cotton production this year was expected to be 270,000 tonnes and Aico would buy 50 percent of the crop.

"If we start producing GMOs and the quality of inputs to farmers increases, there is nothing that will stop us from producing (1 million tonnes)," Devenish told Reuters on the sidelines of a foreign investor conference in Harare.

"That will be four percent of the world's cotton output."

He said the government had accepted in principle to allow the growing of GMO cotton.

Small-scale farmers, who number about 100,000, produce the bulk of Zimbabwe's cotton and Aico provides seed and fertilisers to most of them, who are contracted to sell their crop to the company.

Devenish said Aico had secured $200 million from foreign banks to finance the purchase of cotton from farmers this year.

The cotton industry is the only agriculture sector not affected by President Robert Mugabe's seizures of white-owned commercial farms in 2000 which disrupted commercial farming.

Chinese firms started buying cotton directly in Zimbabwe last year but were accused of purchasing crops from farmers contracted by local companies.

"We had a problem with the Chinese who bought the crop against the requirements of the legislation but this year the Ministry of Agriculture intervened and things are now ok," he said.

Aico, a majority shareholder in one of Africa's largest maize seed producers, Seed Co Ltd, said it was poised to expand on the African continent where Seed Co already has a presence.