INTC -0.30 % Intel Corp. INTC -0.30 % is nearing the sale of a majority stake in its McAfee unit to private-equity firm TPG, a deal that would value the computer-security business at about 4.2 billion including debt, people familiar with the matter said. TPG will take a 51% stake in the business, while Intel will retain 49%, according to one of the people. The transaction is expected to be announced as soon as Wednesday, the people said. Intel bought McAfee in 2011 in a 7.7 billion deal as the chip giant sought to diversify. The continuing decline in personal computers has forced Intel to focus on growth areas such as computers for data centers and noncomputer devices outfitted with data-processing and communications capabilities, known as the Internet of Things.