Dell has agreed to buy information technology services company Perot Systems for $3.9 billion, it has been announced. Round Rock, Texas-based Dell has offered $30 a share in cash for Perot, around 31 times its earnings in 2009. Plano, Texas-based Perot, which manages computer systems, data centers, software and websites for its clients, achieved sales of $2.78 billion last year. The deal reflects DellÔÇÖs desire to move beyond the personal computer business and expand into services and more specifically, the healthcare industry.