Complex sentence: Foster Yeoman Limited, based in the United Kingdom, was one of Europe's largest independent quarrying and asphalt companies, but is now part of Aggregate Industries, owned by the Swiss construction materials conglomerate Holcim.
Split into simpler sentences: Foster Yeoman Limited, based in the United Kingdom, is one of Europe's largest quarrying and asphalt companies. It is owned by the Swiss construction materials conglomerate Holcim.