Robbins Umeda LLP has commenced an investigation into possible breaches of fiduciary duty and other violations of state law by members of the Board of Directors ("Board") of ArcSight, Inc. ("ArcSight" or the "Company") (NASDAQ: ARST) in connection with their efforts to sell ArcSight to Hewlett-Packard Company ("Hewlett-Packard") (NYSE: HPQ).  If the transaction is completed, ArcSight shareholders will receive $43.50 in cash for each share of ArcSight common stock they hold.  The transaction is expected to close by the end of the calendar year.

Robbins Umeda LLP's investigation concerns whether the ArcSight Board undertook a fair process to obtain fair consideration for all shareholders of ArcSight.  Specifically, our investigation concerns whether the Company's Board breached their fiduciary duties to ArcSight shareholders by failing to adequately shop the Company before entering into the transaction with Hewlett-Packard.  Notably, ArcSight's first quarter earnings per share of $0.18 was significantly higher than Wall Street's consensus estimates of $0.13.  In light of this strong quarter, management raised its annual outlook to revenue growth above 20% for the Company's 2011 fiscal year.

If you are a shareholder of ArcSight, plan to continue to hold your shares, and would like more information about your rights as a shareholder, please contact attorney Gregory E. Del Gaizo at 800-350-6003 or by e-mail at info@robbinsllp.com.