110 NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS FOR THE YEAR ENDED 30 JUNE 2011 (d) Segment liabilities reconciliation to the statement of financial position (c) Segment assets reconciliation to the statement of financial position (b) Segment net operating profit/(loss) after tax reconciliation to the statement of  comprehensive income 2011 2010 Executive management meet on a regular basis to assess the performance of each segment  by analysing the segment's net operating profit after tax. A segment's net operating profit  after tax excludes non operating income and expense such as dividends received, fair value  gains and losses, gains and losses on disposal of assets and impairment charges. Income  tax expenses are calculated on the segment's net profit or loss. Reconciliation of segment net operating loss after tax to net profit/(loss) before tax : Segment net operating profit/(loss) after tax 15,137,769  (3,107,428) Income tax expense (192,014) 1,447,101  Share of loss of associates 221,092  (127,475) Finance costs (394,920) (1,145,058) Corporate expenses (3,637,636) (3,050,362) Impairment of assets (17,358,674) - (Loss)/gain on deemed disposal of associate 14,788,837  1,207,775  Exploration and evaluation expenditure written off (1,151,466) (254,475) Fair value gain on financial instruments (57,464) (57,464) Net gains on disposal of available-for-sale investments 55,717,781  34,035  Net gain on disposal of assets (463,516) 19,101,536  Total net profit before tax per statement of comprehensive income 62,609,789  14,048,185  In assessing the segment performance on a regular basis, executive management analyses the segment result as described above in  relation to segment assets. Segment assets are those operating assets of the entity that management views as directly attributing to  the performance of the segment. These assets include plant, equipment, receivables, inventory and intangibles and exclude available- for-sale assets, derivative assets and deferred tax assets. Reconciliation of operating assets to total assets: Segment liabilities includes trade and other payables and debt. The Consolidated Entity has a centralised finance function that  is responsible for raising debt and capital for the entire operations. Each entity or business uses this central function to invest  excess cash or obtain funding for its operations. Executive management reviews the level of debt for each segment on a regular  basis. Reconciliation of operating liabilities to total liabilities: Segment operating liabilities 10,188,438  15,923,642  Liabilities of disposal group classified as held for sale 886,260  886,260  Total liabilities per the statement of financial position 11,074,698  16,809,902  Segment operating assets 224,319,383  183,062,485  Available-for-sale assets 49,004,755  34,064,803  Derivative assets 228,269  57,464  Assets of disposal group classified as held for sale 1,476,212  1,491,219  Total assets per the statement of financial position 275,028,619  218,675,971 