Clearlake Capital Group said on Monday it would buy Quest Software from Francisco Partners, as the investment firm seeks to tap into the pandemic-spurred surge in demand for enterprise software and cybersecurity tools. The deal values Quest at US$5.4 billion, including debt, a source familiar with the matter told Reuters. Quest, which counts companies like Microsoft Corp, Ford Motor Co and Merck & Co as its customers, provides solutions spanning from database management to data protection to IT departments.