Samsung Electronics Co Ltd recently approached BlackBerry Ltd about buying the company for as much as $7.5 billion, looking to gain access to its patent portfolio, according to a person familiar with the matter and documents seen by Reuters. South Korea's Samsung proposed an initial price range of $13.35 to $15.49 per share, which represents a premium of 38 percent to 60 percent over BlackBerry's current trading price, the source said.