European private equity fund CVC and Singaporean sovereign wealth fund Temasek [TEM.UL] are to buy a controlling stake in the pharmaceutical firm Alvogen, its chairman and chief executive said. Robert Wessman, former CEO of Actavis, founded the New Jersey-based generic drugs firm in 2009. The transaction is the latest sign of the hectic pace of deal-making in the healthcare sector, which has seen more than $250 billion of mergers and acquisitions so far this year, up nearly two-thirds from a year ago, according to Thomson Reuters data.