DESIRE Petroleum shares fell in London after the company announced Ocean Guardian may leave the South Atlantic early next year.

Platts' online news and analysis said Desire stated Diamond Offshore was in discussions with a third party which might result in the Ocean Guardian rig leaving the Falkland Islands in Q1 2012.

Following the update, Desire shares fell in London and were trading 5.4% lower at GBP19.62 by 0940 GMT.

Earlier this month, Desire agreed a farm out deal with Rockhopper allowing it to drill an exploration well on what it believes is an extension to Rockhopper's landmark Sea Lion discovery.

"The farm-out agreement with Rockhopper announced on 12 October 2011 will ensure that at least one well is drilled on this acreage in the current drilling campaign," chairman Stephen Phipps said in the statement.

Desire also said it has identified 11 oil prospects holding best estimate recoverable resources of 638 million barrels of oil with new seismic over part of its acreage in the North Falkland Basin.

Citing a competent person's report (CPR) based on new 3D seismic covering 40% of its exploration acreage in the Falklands, Desire said recoverable resources net to the company stand at 322 million barrels.

The prospect sizes range from 15 to 132 million barrels and include a possible extension of Falkland's Sea Lion oil discovery with gross best estimate potential of 59 million barrels, the company said.

Desire said the report estimates that, at $85/b realized oil price, the minimum economic threshold for a prospect is 43 million recoverable barrels for a stand-alone development and 10 million barrels for a sub-sea tie back development.

"The CPR summary published today confirms our belief in the prospectivity of the fast track areas of PL003 and PL004," Phipps said in the statement