XCITE Energy has issued an improved forecast for its Bentley heavy oil field east of Shetland as it reported a widening of first quarter losses.

North Sea-focused Xcite said the latest assessment announced on April 30 put proven and probable reserves at 265 million stock barrels (MMstb) - eight MMstb higher than previously estimated in February.

It confirmed that the net present value of reserves in the Bentley field was about US $1.9 billion, $2.3bn, and $2.6bn on a proven, probable and possible basis.

The update came as the company, which is seeking venture partners to develop the field. reported a widening of first quarter net losses to $0.5m, from $0.1m in the three months ended March 31, 2014.

Xcite chief executive Rupert Cole said: "The reserves report is significant for us, as it incorporates much of the work we have completed over the past year with the development group, providing external validation to the recovery in the field, the development plan and execution strategy.

"Full field unescalated costs are expected to be approximately US$35 per barrel [and] have been underpinned by third party quotes and estimates in order to increase the visibility of the robust economics of this development plan for the Bentley project.

"We remain focused on developing the funding required to crystallise value from this asset."

Shares in Xcite Energy closed down 1.5p, or 3.97 per cent, at 36.25p.