This excerpt taken from the ICI 6-K filed Mar 21, 2007.
(b) Purchase accounting adjustments, including the amortisation and impairment of goodwill and intangibles
The accounting policy for goodwill is similar between IFRS and US GAAP, with goodwill arising on acquisitions capitalised and reviewed for impairment annually and whenever indicators of impairment arise. The methodology for testing impairment differs between IFRS and US GAAP. However, due to the historic differences in accounting between UK GAAP and US GAAP for goodwill and other intangibles, relating mainly to amounts capitalised and amounts amortised, the Group has recognised significantly more goodwill on the balance sheet under US GAAP compared to IFRS. As a result, disposals of goodwill, any impairments and exchange on retranslation of goodwill may vary between IFRS and US GAAP.
The historic differences in accounting between UK GAAP and US GAAP for goodwill and other intangibles relate to:-