Looks like the Bar Chars industry groupings are based around the SIC (Standard Industry Classification) codes.
This classification system, whilst popular in Government circles, is not widely used on the market.
It seems that the various companies involved in the classifications (S&P, Dow Jones etc.) have a vested interest in performing the classifications on these companies so that managed funds, exchange traded funds, indices and derivatives on indices (futures & options) can be made against them.
In the UK, FTSE Group (makers of the FTSE index) seem to dominate the market but look like they also want to expand globally.
Cheers,
Richard.