WILSONVILLE, Ore. — (BUSINESS WIRE) — April 25, 2011 — Mentor Graphics Corp. (NASDAQ: MENT) today issued the following open letter to the shareholders of Mentor Graphics regarding the company’s Annual Meeting of Shareholders scheduled for May 12, 2011.

The Mentor Graphics Board strongly recommends that Mentor Graphics shareholders vote FOR the company’s director nominees on the WHITE proxy card and discard any proxy materials received from Carl Icahn.

April 25, 2011

Dear Fellow Mentor Graphics Shareholders:

Our Annual Meeting of Shareholders is less than three weeks away. Your Board of Directors urges you to support the team that has delivered excellent results and created value for shareholders.

Carl Icahn is trying to replace three of Mentor Graphics’ nominees with his own, hand-picked nominees. Icahn’s primary aim is to provide himself with liquidity through a public sale process that is risky and is likely to destroy the shareholder value that your company has created.

SUPPORT THE BOARD THAT HAS DELIVERED EXCELLENT RESULTS AND VALUE CREATION BY ELECTING MENTOR GRAPHICS’ NOMINEES

Under the leadership of your current Board, Mentor Graphics has focused on areas of EDA where we have number one positions or the potential to have number one positions and high growth non-traditional EDA markets such as transportation. We are confident that by continuing to execute this strategy, Mentor Graphics’ growth will continue to exceed the underlying growth of traditional EDA. The strength of this strategy is reflected in Mentor Graphics’ stock price, which has outperformed its two closest competitors — Synopsys, Inc. and Cadence Design Automation, Inc. — and general market indices, over the relevant one, three and five year periods.