Dublin-based San Leon Energy said on Tuesday it was inviting bids for a stake in its Albanian exploration licence, which it said could hold over a billion barrels of oil, after receiving a number of unsolicited bids.

The company said in a statement it had opened a data room for prospective bidders and was in talks with several large E&P companies.

San Leon's London-listed shares traded up 12 percent at 11.33 pence at 08:52 a.m. BT.

The group did not say how much it expected to raise but such deals are usually cut on the basis that the purchaser agrees to cover all or part of the seller's share of field exploration and development costs.

From the early 1990s, a number of international oil companies including Chevron , Occidental , ENI and Royal Dutch Shell explored in Albania but with disappointing results.

In recent years a number of small explorers including PetroManas
and Stream Oil & Gas have returned to the country and taken up the drilling effort.

The companies have cited multi-billion barrel potential reserves.

However, the U.S. government's Energy Information Administration records the country as having only 200 million barrels of proven reserves and the BP Statistical Review of World Energy ascribes no reserves to Albania.

Nonetheless, Canada's Bankers Petroleum has brought production on-stream and is currently pumping around 15,000 barrels per day. Cairn Energy , considered one of the UK's most successful explorers has also bought exploration licences in the country but has yet to begin work there.

(Reporting by Tom Bergin; Editing by Mike Nesbit and Hans-Juergen Peters)