(ShareCast News) - Shares in Circle Oil tanked on Friday after it said that given its $77.5m outstanding debt position and based on the indicative proposals received to date, the outcome of the strategic review is likely to be little or no value to equity holders.The AIM-listed oil and gas exploration company said it has received a number of indicative proposals, which are in the process of being evaluated, and is working to conclude the strategic review process as expediently as possible. Circle said management was continuing to consider all options to maximise value for shareholders and stakeholders, including a debt restructuring, a sale of one or more of its existing assets, a merger with a third party, the sale of the entire issued, and to be issued, share capital of the company and a subscription for new shares.The group's debt comprises a $20m convertible loan held by KGL Investment Company and a $57.5m reserve base lending facility with International Finance Corporation which is fully drawn.At 1000 BST, Circle Oil shares were down 75% to 0.51p.