Mosaic, the world's biggest phosphate producer, dispersed some of the cloud hanging over a key mine by agreeing concession with environmental campaigners, whose victory in a court battle forced the closure of the site.

The fertilizer giant said it had won temporary agreement with the three environmental groups to restart mining on 200 acres of contested ground at its South Fort Meade mine in Florida. In return, Mosaic agreed not to mine 40 acres, much of which will be set aside as a conservation area.

The deal, provided it wins necessary court consent, will allow Mosaic to reopen a mine which accounts for one-third of the group's phosphate rock capacity, and whose "indefinite" mothballing since September has fuelled a rise in prices of the nutrient.

Shares in the group rose by 4.3% on Wednesday last week after Citigroup analysts lifted to "buy" from "hold" their rating on Mosaic shares, and lifted their target on the stock to $78 from $64, on hopes for a resolution of the South Fort Meade dispute.

However, the realisation of the compromise failed to provoke a similar reaction, with the stock closing 0.3% lower at $70.39 in New York.

Court battle continues 

However, the agreement fails to represent an end to Mosaic's battle at South Fort Meade, with the agreement lasting for only "an estimated" four months while the group contests the July court ruling which forced it to close the mine.

The court prevented the company from relying on a mining licence issued by the US army even though, according to Mosaic general counsel Richard Mack, the document represented "the most extensive and environmentally protective phosphate mining permit in Florida's history".

The group also highlighted that one month of the four outlined in the deal will be spent reopening the mine, before it restarts deliveries of phosphates.

Nonetheless, Mr Mack termed as "sensible" the compromise reached with environmentalists, which will eases the threat of further job losses at the site.

"As we move forward, we aim to continue a constructive dialogue with the environmental community to promote a better understanding of our respective interests," he added.