London-listed cybersecurity firm Sophos is to be bought by US private equity firm Thoma Bravo in a deal worth £3.1bn, including its net debt.

The US firm said it would take Sophos private as part of a wider strategy which has included 200 acquisitions collectively worth more than $50bn.

Oxfordshire-based Sophos supplies cybersecurity solutions to mid-market businesses and SMEs. It currently has more than 400,000 customer in over 150 countries. It floated in 2015 for £1bn.

"It is the view of the Sophos board this is a compelling offer for Sophos shareholders which secures the delivery of future value for shareholders today,” said Peter Gyenes, chair at Sophos.

“Thoma Bravo has deep sector expertise in cybersecurity software as well as a long and successful track record of partnering with and investing in its portfolio companies to support long-term growth and success.

"Under Thoma Bravo's ownership, we expect Sophos to accelerate its evolution and leadership in next-generation cybersecurity. The Sophos board believes this recommended offer delivers a significant opportunity for all stakeholders, our shareholders, customers, partners, and employees."

San Francisco-based Thoma Bravo has been focussed on on cybersecurity buy outs having already acquired California-based Sophos rival Barracuda Networks in 2017, in a deal then worth $1.6bn.

Shares of FTSE 250 firm Sophos were seen up 30 per cent following the announcement – a positive direction for the firm after losses in 2018 and a swing back to profitability at the beginning of the year.

It said it expects to report 9 per cent constant currency billings growth - the value of products and services invoiced to customers - for the six months to the end of September.

“Today marks an exciting milestone in the ongoing journey of Sophos,” said Kris Hagerman, CEO, Sophos.

“Sophos is actively driving the transition in next-generation cybersecurity solutions, leveraging advanced capabilities in cloud, machine learning, APIs, automation, managed threat response, and more.

"We continue to execute a highly-effective and differentiated strategy, and we see this offer as a compelling validation of Sophos, its position in the industry and its progress.”

In July, the firm’s CFO Nick Bray announced his intention to leave the cybersecurity firm next month.