The end to Thomson's 11 years at the company follows the sell-off of AOL Europe's ISP business, in which she played a major role. Thompson joined AOL in 1995 as UK marketing director in the year prior to its launch.
Carphone Warehouse won the auction for AOL UK's ISP business last month, and the sale is due to complete by the end of the year.
AOL is now in the process of recasting itself as a portal-only business in the UK, France, Germany and the Netherlands.
The Italian-born d'Asaro Biondo will have ultimate responsibility for AOL UK, but its day-to-day operations will be handled by the six-strong senior management team. The team comprises: Tobin Ireland, chief marketing officer; Andy Jonesco, senior vice-president for audience; Dan Constanda, group finance director; David Carr, senior vice-president for access; John Shaw, vice-president for human resources and Colin McQuade, vice-president for technology.
Thomson retained responsibility for the UK when she was promoted to European president from UK chief executive and chairman in May, so there will be a void in the UK chief executive position.
An AOL spokesman said he could not say whether there will be a role for a UK chief executive until the company completes its restructuring plans.
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