Complex sentence: Transocean was rated as a leader in its industry for many years; however, since its merger with GlobalSantaFe in 2007, its reputation has suffered considerably, according to Energy Point Research, an independent oil service industry rating firm.
Split into simpler sentences: Transocean was rated as a leader in its industry for many years. However, since its merger with GlobalSantaFe in 2007, its reputation has suffered considerably, according to Energy Point Research, an independent oil service industry rating firm.