Dell has bought SecureWorks which provides a variety of security and compliance services to customers including 85 of the Fortune 500 companies and many banks and financial institutions.
The company offers threat assessment and managed security for large and medium-sized companies.
SecureWorks, started in 1999, employs 700 people, including several respected researchers.
The company is based in Atlanta, Georgia but also has offices in Chicago, London and Edinburgh.
Its European business got a boost when it bought UK security services provider dns in 2009.
The company said the deal with Dell would give it a chance to rapidly expand.
SecureWorks sells via the channel - Dell began selling its services to mid-sized firms in July last year.
Last year it also hired ex-Oracle exec Eddie Chance to beef up its channel sales in Europe.
Financial terms of the takeover were not disclosed, but Dell did say SecureWork expected sales of $120m for 2010.