Perth-based Tap said this included possibly divesting its flagship Manora Oil Development in the Gulf of Thailand plus the company's non-core Australian portfolio.

"The strategic review process will also consider any potential whole of company proposals that may emerge, should they provide compelling value for Tap shareholders," the company said.

"This follows the valuation outcomes achieved by shareholders in other ASX-listed companies with Australian and Asian oil production portfolios through change in control transactions over the last 12 months (such as Fosun's acquisition of Roc Oil and Bangchak's acquisition of Nido Petroleum).

"Tap has appointed Miro Advisors in respect of the Australian asset portfolio divestment options, and Corrs Chambers Westgarth to assist with the strategic review process."

Meanwhile, Tap has separately issued a letter to shareholders today which slammed Yenbamroong, who owns joint venture partner Northern Gulf Petroleum and who recently increased his holding in Tap from 6% to 19.98%.

"Mr Yenbamroong is proposing to appoint 80% of the Tap Board when he only has voting control over 19.98% of Tap shares," Tap non-executive director Douglas Schwebel wrote.

"The Tap board is unanimous in its view that this is an opportunistic attempt by Mr Yenbamroong to take control of your company without making a formal offer and paying a control premium to all Tap shareholders."

He also said any meeting of shareholders over the matter was likely to be held in either late April or early May.