The sale price represents a 37 percent premium on the Sophos market trading price, traditional Sophos board of directors said they plan to "unanimously recommend" the acquisition offer to their shareholders.
Before today's announcement, Thoma Bravo acquired a minority stake in McAfee last year and was rumoured to be interested in buying the whole company.
It is unclear how today's Sophos acquisition will impact plans to buy McAfee, but the two companies -- Sophos and McAfee -- are classic rivals on the cyber-security market and share a product portfolio, so the door seems to have closed on the McAfee deal.
Thoma Bravo was founded in 2003 and has quickly risen to become a significant player on the capital market with more than 230 deals, mostly based around software, IT infrastructure, and cyber-security.
Thoma Bravo also acquired storage, backup, and security appliance vendor Barracuda Networks for $1.6 billion in November 2017; software testing firm Veracode for $950 million in January 2019; DDoS mitigation firm Imperva for $2.1 billion in January 2019; and software firm ConnectWise for $1.5 billion in February 2019.