Crawley, UK -- (MARKET WIRE) -- October 13, 2006 --

Spirent Communications Plc
Transaction in Own Shares

Spirent Communications PLC announces that it has today purchased through
Citigroup Global Markets U.K. Equity Limited 1,000,000 ordinary shares at an
average price of 59.611 pence per share. The highest price and the lowest price
paid for these shares were 60.0 pence and 58.75 pence respectively.

Following the above purchase, Spirent Communications plc holds 70,790,000
Spirent Communications plc ordinary shares in treasury, and has 832,403,551
Spirent Communications plc ordinary shares in issue (excluding treasury shares).

                      This information is provided by RNS
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