(ShareCast News) - Shares in San Leon Energy surged over 15% early on Monday, after the oil and gas explorer confirmed speculation over a potential takeover.On Sunday, Irish newspaper the Daily Business Post reported the London-listed group was "being targeted for takeover".The company confirmed the speculation on Monday, although it said there was no guarantee a deal will be completed."The board of San Leon confirms that it has received an approach from a possible offerer, that may or may not lead to an offer being made for San Leon," it said in a statement.San Leon shares were up 16.50% to 62.33p at 0903 BST on Monday.