AMIS Amis Holdings (MM)

AMIS Holdings, Inc. (NASDAQ: AMIS), and ON Semiconductor Corporation (NASDAQ: ONNN) today announced that the Securities and Exchange Commission has declared effective the Registration Statement on Form S-4 relating to the proposed merger between AMIS Holdings (“AMI”) and ON Semiconductor (“ON”) as of February 8, 2008. As previously announced, AMI and ON have entered into a definitive merger agreement under which ON would acquire AMI in a stock-for-stock merger. Under the terms of the agreement, each outstanding share of AMI common stock would be exchanged for 1.15 shares of ON common stock.

AMI stockholders of record as of the close of business on February 8, 2008 will be mailed the definitive proxy statement/prospectus in connection with the proposed merger with ON and will be entitled to vote at the special meeting of AMI stockholders. The special meeting of AMI stockholders to consider and vote upon the proposed merger with ON has been scheduled for March 12, 2008 at 9:30 a.m., local time, at the Grand America Hotel, 555 South Main Street, Salt Lake City, UT. The transaction is expected to close as soon as practicable under the terms and conditions of the merger agreement, which include, among other things, a requirement that each of AMI’s and ON’s stockholders approve the merger.

AMI stockholders are encouraged to read the definitive joint proxy statement/prospectus in its entirety as it provides, among other things, a detailed discussion of the process that led to the proposed merger and the reasons behind the AMI Board of Directors’ unanimous recommendation that AMI stockholders vote FOR the adoption of the merger agreement.