Transaction in Own Shares

Spirent Communications PLC
21 July 2006


Spirent Communications plc announces that on 21 July 2006 it purchased from
JPMorgan Cazenove Limited 700,000 Spirent Communications plc ordinary shares at
an average price of 34.4525 pence per share. The purchased shares will be held
as treasury shares. Following the above purchase, Spirent Communications plc
holds 32,440,000 Spirent Communications plc ordinary shares in treasury, and has
938,435,758 Spirent Communications plc ordinary shares in issue (excluding
treasury shares).


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