Complex sentence: In 2006 Whitbread sold a majority of the standalone Beefeater sites (along with standalone Brewers Fayres), as they weren't as popular as sites with a neighbouring Premier Inn.
Split into simpler sentences: In 2006 Whitbread sold a majority of the standalone Beefeater sites (along with standalone Brewers Fayre's). These sites weren't as popular as sites with a neighbouring Premier Inn.