Sale of Monitor Labs Incorporated

812 - 30 September 2002

                                  SPIRENT PLC                                  

                       SALE OF MONITOR LABS INCORPORATED                       

Spirent plc (LSE: SPT; NYSE: SPM), a leading international network technology
company, announces that it has sold Monitor Labs Incorporated (MLI) from within
its Systems group to a subsidiary of Teledyne Technologies Incorporated (NYSE:
TDY) for a cash consideration of $24.0 million (approximately £15.4 million).

MLI, with locations in Colorado and Pennsylvania, USA, is a leading supplier of
environmental monitoring instrumentation and integrated systems. For the year
ended 31 December 2001 MLI had sales of $28.0 million. MLI has approximately
160 employees and will become part of the Teledyne Instruments group of
companies.

As at 31 December 2001 the book value of the business being sold was £1.6
million with associated reinstated goodwill of £32.6 million.

Nicholas Brookes, Chief Executive of Spirent, said:

'MLI has a strong position in its market and will benefit from ownership by a
company that can obtain strategic and synergistic benefits.'

                                   - ends -                                    

Enquiries

Nicholas Brookes, Chief Executive Spirent plc            [phone]    
                                                                               
Eric Hutchinson, Finance Director                                              
                                                                               
Investor Relations                                                             
                                                                               
Catherine Nash                    Spirent plc            [phone]    
                                                                               
Media                                                                          
                                                                               
Jon Coles/Rupert Young            Brunswick (London)     [phone]   
                                                                               
Lauren Teggelaar                  Brunswick (New York)   [phone]       

About Spirent

Spirent plc is an international network technology company providing
state-of-the-art systems and solutions for a broad range of customers
worldwide. Our Communications group is a worldwide provider of integrated
performance analysis and service assurance systems for next-generation network
technologies. Spirent's solutions accelerate the development and deployment of
network equipment and services by emulating real-world conditions and assuring
end-to-end performance of large-scale networks. Our Network Products group
provides innovative solutions for fastening, identifying, insulating,
organising, routing and connectivity that add value to electrical and
communication networks in a wide range of applications. Our Systems group
offers integrated product solutions for the aerospace and power controls
markets. Further information about Spirent plc can be found at www.spirent.com

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York Stock Exchange (ticker: SPM; CUSIP number: 84856M209) with one American
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