Since January 2 2006, FTSE has based its classification system for trading and investment decisions on the International Classification Benchmark (ICB), devised by FTSE and DJ Indexes. This classification system is used for the sectoral data published by the FT.
The stock listings are also based on this system but since early February 2007 - ans purely for stock listings - some sectors have been merged or renamed for clarity.
A comprehensive list of UK companies showing their ICB sector and the sector after the change appears on the Excel spreadsheet contained in the link below.
The nesting of the breakdown of the ICB sectors can also be viewed in Excel at the link below.