Item 1.01. Entry into a Material Definitive Agreement.
On November 18, 2009, ArcSight, Inc. (the "Company") and ECI Two Results LLC (the "Landlord"), entered into a First Amendment to Lease (the "Lease Amendment") modifying certain terms to the Lease Agreement dated as of April 24, 2007 by and between the Company and the Landlord (the "Original Lease"), relating to the Company's corporate offices located at Five Results Way and Four Results Way, Cupertino, California. The Lease Amendment increases the total size of the Company's headquarters to approximately 116,000 square feet by adding approximately 37,000 square feet of space on the first and second floors of the building located at Six Results Way (the "Expansion Premises"). The Lease Amendment requires certain improvements to be constructed and installed in the Expansion Premises and the Company and the Landlord expect the Company to take possession of the Expansion Premises on or about May 1, 2010. The Company's monthly base rent, beginning on May 1, 2010 for the existing premises and on the date the Company takes possession of the Expansion Premises (the "Expansion Date") for the Expansion Premises, will be set at $2.06 per square foot, a reduction of $0.02 per square foot from the base rent set forth in the Original Lease, and will increase at a rate of 3% per year, rather than the 4% rate under the Original Lease. The term of the Original Lease, which was scheduled to expire on October 31, 2013, is now through 84 months after the Expansion Date. The Company is also entitled to a right of first offer on any other space located at Six Results Way.
The above description of the Lease Amendment is qualified in its entirety by reference to the full text of the Lease Amendment, a copy of which will be filed as an exhibit to the Company's next periodic report on Form 10-Q.

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