This excerpt taken from the SYT 20-F filed Mar 1, 2006.
Uncertain tax positions
Syngentas estimates of current income tax expense and liabilities are calculated on the assumption that all tax computations filed by Syngentas subsidiaries will be subject to review or audit by the relevant tax authorities. Current income tax liabilities include Syngentas best estimate of the tax that will ultimately be payable when the reviews or audits have been completed, including allowances for interest and penalties which Syngenta may be required to pay if the authorities assess additional tax payments for prior years. Actual outcomes and settlements may differ significantly from the estimates recorded in these consolidated financial statements. This may affect current income tax expense, net income, effective tax rates and earnings per share reported in future years consolidated income statements. Several prior years tax computations are generally still open for review or audit for most Syngenta subsidiaries at the balance sheet date. Syngenta has insufficient historical data to quantify accurately the amount of any future changes which may be required to the current income tax liability as a result of any settlements with tax authorities which may occur within the next financial year. At December 31, 2005, Syngentas balance sheet included assets of US$48 million (Note 10) and liabilities of US$323 million, shown separately on the face of the balance sheet, for current income taxes.