The chief marketing officer at Ukrainian iron ore producer Ferrexpo has resigned.Simon Wandke who joined the Swiss headquartered resources giant in 2006, will leave at the end of the year."On behalf of the board I would like to thank Simon for his significant contribution to the company," said chairman Michael Abrahams.The 48-year-old was Vice President Strategy for the Minerals Group and Vice President Coal, Iron Ore and HBI Marketing at BHP Billiton until 2001.Up until joining Ferrexpo he was a partner of Destra Consulting Group, in Melbourne, specialising in change management."The board is well advanced in a search for Simon's replacement and is committed to ensuring a smooth and effective handover," the firm said.