Crawley, UK -- (MARKET WIRE) -- November 16, 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 600,000 ordinary shares at an average price of 58.1685 pence per share. The highest price and the lowest price paid for these shares were 58.75 pence and 57.5 pence respectively.

Following the above purchase, Spirent Communications plc holds 88,451,487 Spirent Communications plc ordinary shares in treasury, and has 887,000,064 Spirent Communications plc ordinary shares in issue (excluding treasury shares).

                      This information is provided by RNS
            The company news service from the London Stock Exchange