Stock index provider S&P Indices has announced Atlas Iron and Equinox Minerals have joined the ranks of the top 100 Australian companies, while five other Western Australia-based firms have been elevated to the S&P/ASX 300.

Stock index provider S&P Indices has announced Atlas Iron and Equinox Minerals have joined the ranks of the top 100 Australian companies, while five other Western Australia-based firms have been elevated to the S&P/ASX 300.