Private equity investment firm Thoma Bravo on Wednesday announced that it has acquired Tripwire, a maker of network security and compliance automation solutions.

Financial terms of the deal, which is expected to close by the end of the month, were not disclosed. Tripwire, headquartered in Portland, Ore., will continue operate as an independent entity, with Jim Johnson, the company's CEO, remaining in his current role. 

The acquisition means Tripwire, founded in 1997, has scrapped plans to go public after filing last year for an $86 million initial public offering on the Nasdaq stock exchange.

Meanwhile, Thoma Bravo continues to grow its portfolio as companies choose not to go public in light of costs, regulations and shareholder expectations.

Thoma Bravo purchased LANDesk, an enterprise IT management solutions provider, in August 2010 and acquired Entrust, a provider of encryption and digital certificates, in April 2009.

“Tripwire and Thoma Bravo are aligned in our goals to continue growing the company,” Johnson said in a statement Wednesday. “The backing by Thoma Bravo allows us to stay focused and accelerates our vision.”

Tripwire is a provider of integrated file integrity, policy compliance and log and event management solutions. The company counts more than 5,700 government, businesses and service provider customers in 94 countries and serves 46 percent of Fortune 500 companies, according to a news release issued Wednesday.