World's No.3 personal computer maker Dell Inc (Nasdaq: DELL) said it would buy SonicWall, a maker of firewall, email protection and recovery products, from an investor group, to expand its security software business.

Financial terms of the deal were not disclosed.

SonicWall was a public company until 2010, when it got acquired by an investor group led by Thoma Bravo for $717 million.

During our ownership of the company, their implementation of our operational strategies resulted in a significant increase in SonicWalls' value, Thoma Bravo managing partner Orlando Bravo said in a statement.

Dell shares were up 14 cents at $17.10 in morning trade on Tuesday on the Nasdaq.

(Reporting by Monika Shinghal in Bangalore; Editing by Gopakumar Warrier)