Complex sentence: Actis Capital is a private equity investment firm, headquartered in London, United Kingdom, specializing in investments in developing countries, whose investment portifolio was almost US $5 billion, as of April 2010.
Split into simpler sentences: Actis Capital is a private equity investment firm, headquartered in London, United Kingdom, that specializes in investments in developing countries. The firm's investment portifolio was almost US $5 billion as of April 2010.