Shares in Agriterra surged 18% after the group revealed greater operational success in four months as a farming business than it managed in four years in its former incarnation as an oil prospector.

The group, which is chaired by former England cricketer Phil Edmonds, said it had succeeded in getting a second Mozambican corn mill, Compagri, into operation. The first, Deca, it bought in working order.

Compagri has begun turning maize into flour at a rate of 80 tonnes a day, with plans to raise throughout to 120 tonnes day.

While a modest set forward by the standards of many agriculture companies, the launch represents a milestone for Agriterra which, in its previous guise of oil company White Nile, failed to report 1 penny of revenues after it was floated in 2005.

While White Nile bought a 60% stake in a potentially lucrative oilfield , Block Ba, in southern Sudan, the deal was struck with rebels, who are yet to get into legitimate government. Total, the French oil giant, also claims rights to Block Ba.

'Spreading risk'

Andrew Groves, the Agriterra chief executive, said that the opening of Compagri "should continue significantly to our operational and financial performance".

The group is also considering readying the plant to handle other crops, including ground nuts.

"The diversification of the product range will strengthen the company's growth strategy by enabling year round processing of a variety of productions, ultimately spreading any potential risk," the company said.

Agriterra shares, which reached a high of 205p and a low of less than 1p during its White Nile years, closed up 0.6p at 4.0p in London.