Blue Coat Systems, a provider of Web security and WAN optimization solutions has entered into a definitive agreement for acquisition by an investor group led by San Francisco-based private equity investment firm Thoma Bravo.

The transaction is valued at approximately $ 1.3 billion. The Blue Coat Board of Directors has approved the agreement and resolved to recommend that the shareholders of Blue Coat adopt this agreement. Blue Coat will continue to operate with its focus on Web security and WAN optimization.

The investor group is led by Thoma Bravo and includes the Ontario Teachers’ Pension Plan through its private investor department, Teachers’ Private Capital.

Under the terms of the agreement, Blue Coat shareholders will receive $ 25.81 in cash for each share of Blue Coat common stock they hold, representing a premium of approximately 48% over Blue Coat’s closing price on December 8, 2011 and a premium of approximately 62% over the 60-day trailing average for the period ending Dec.8, 2011.

“Over the last six months, our Board of Directors engaged in a comprehensive review of all strategic options available to Blue Coat.” – David W. Hanna Chairman of the Board Blue Coat Systems

“After an extensive evaluation of strategic alternatives with our independent advisors, the Board has determined that the definitive agreement with Thoma Bravo provides an attractive all-cash valuation to our shareholders. We look forward to completing the transaction under the terms of the agreement as expeditiously as possible,” he added.

“Blue Coat has strong, differentiated products for protecting enterprises from the ever increasing levels of Web-based security threats and for accelerating and optimizing applications and rich media content, such as video, over their networks.” – Gregory S. Clark president and chief executive officer Blue Coat Systems

“Our partnership with Thoma Bravo will assist Blue Coat in more aggressively realizing the opportunities in its two markets, by providing a platform that enables greater focus on the business that supports the future growth of the company,” he said.

The transaction is subject to customary closing conditions, including requisite regulatory approvals and approval of Blue Coat shareholders. Blue Coat expects the transaction to close in the first calendar quarter of 2012