Complex sentence: Haji-Ioannou floated Stelmar Shipping on the NYSE in 2001 and in 2005 it was sold to the OSG Shipping Group for approximately $1.3 billion.
Split into simpler sentences: Haji-Ioannou eventually, in 2001, floated Stelmar Shipping on the NYSE. In 2005, the company was sold to the OSG Group for approximately $1.3 billion.