Ambrian Capital, the natural resources investment firm, has seen its share price plummet 20% following the announcement of a balance sheet loss of £1.46m for the six months to the end of June.The figure includes a complete write down of the group's holding in its investment banking operation known as Ambrian Partners, which equates to a £2.15m impairment. The reasoning for this is what the firm described as "financial turmoil...in global equity markets"The loss suffered on Ambrian Partners is partly behind the decision to award no dividend to shareholders for the half year to June.Net loss per share was 1.49p and the net asset value per share hit 31.48p, up slightly on December 2010 when it stood at 31.14.Chief executive Robert Ashley said: "The weakness and volatility experienced in global equity markets since the end of March 2011 have weighed on the Group's corporate finance and equities division. As a result, the transaction pipeline has been weakened and primary and secondary placement activity significantly reduced with little visibility for a short term upswing."He added: "The board is conscious of the substantial discount at which the Company's share price stands to its net asset value and continues to look at ways of reducing this and otherwise enhancing shareholder value."BS