The Bank of New York 101 Barclay Street, 22nd Floor New York, NY 10286 May 8, 2006 Securities & Exchange Commission 450 Fifth Street, NW Washington, DC 20549 Attn.: Document Control RE: American Depositary Shares evidenced by American Depositary Receipts, each representing four Ordinary Shares of Spirent plc (Form F-6 File No 333-10132) Ladies and Gentlemen: Pursuant to Rule 424(b)(3) under the Securities Act of 1933, as amended, on behalf of The Bank of New York, as Depositary for securities against which American Depositary Receipts are to be issued, we attach a copy of the new prospectus (Prospectus) reflecting the name change of Spirent plc to Spirent Communications plc, effective May 8, 2006. As required by Rule 424(e), the upper right hand corner of the Prospectus cover page has a reference to Rule 424(b)(3) and to the file number of the registration statement to which the Prospectus relates. Pursuant to Section III. B. of the General Instructions to the Form F-6 Registration Statement, the Prospectus consists of the ADR certificate with revised name of Spirent Communications plc. The Prospectus has been revised to reflect the new name of cents by addition of the following notation: Effective May 8, 2006, the Companys name has changed to SPIRENT COMMUNICATIONS PLC. Please contact me with any questions or comments at 212 815-4244.