van Ek's appointment also allows Matthew Battrick, current managing director, to concentrate on all technical, exploration and production matters in his new role as executive director (technical).
Prior to joining Sun, van Ek's most recent position was as chief executive officer of Spyker Energy, an upstream oil company based in London that discovered oil and gas offshore Denmark in 2011.
He has 17 years of upstream oil and gas and related finance experience, and before moving to Spyker he was a business development executive at Genting Oil from 2008 to 2010.
Prior to that, he was regional head of reserves based lending for upstream oil and gas (Asia Pacific) with BNP Paribas in Singapore.
van Ek also previously worked for ANZ Investment Bank in London and later Sydney, where he was an upstream oil and gas specialist from 2001 to 2005 and had petroleum engineering sign off for credit committee lending decisions.
He started his career in 1996 at Shell International E&P as an operations engineer.
Dr Wolf Martinick, chairman, commented: "We are pleased that Govert van Ek has joined the Board at this important time for Sun as the company seeks to grow shareholder value in the Woodbine tight oil play.
"The Board believes the appointment of a managing director with a strong track record of successful oil and gas project development and oil and gas financing is an important and timely step for the company as it evolves from an explorer to a producer."
The company's Woodbine tight oil play includes the Delta, Amerril, Richland and Normangee projects, spread across the Leon and Madison counties.
Most recently, Sun appointed Amerril Energy as the operator of the Richland Oil Project to complete the current work over operations on the project's production wells, to achieve higher flow rate recovery rates.
Sun is well funded with A$8.4 million in cash at the end of December 2012.
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