RNS Number:2668U
Isotron PLC
15 January 2004


                    BLOCKLISTING SIX MONTHLY REVIEW


1. NAME OF COMPANY:     ISOTRON PLC



2. NAME OF SCHEME:      1994 EXECUTIVE SHARE OPTION SCHEME



3. PERIOD OF RETURN:     FROM: 1 JULY 2003    TO: 31 DECEMBER 2003



4. NUMBER AND CLASS OF SHARES(S)
   (AMOUNT OF STOCK/DEBT SECURITY)
   NOT ISSUED UNDER SCHEME
   AT END OF THE LAST PERIOD:          165,000



5. NUMBER OF SHARES ISSUED/ALLOTTED
   UNDER SCHEME DURING PERIOD:         32,500



6. BALANCE UNDER SCHEME NOT YET ISSUED/ALLOTTED 
   AT END OF PERIOD:      133,000



7. NUMBER AND CLASS OF SHARE(S)                    200,000
   (AMOUNT OF STOCK/DEBT SECURITIES)               REF: A/4933/1997
   ORIGINALLY LISTED AND THE DATE OF ADMISSION:    12 DECEMBER 1997


PLEASE CONFIRM TOTAL NUMBER OF SHARES IN ISSUE AT THE END OF THE PERIOD
IN ORDER FOR US TO UPDATE OUR RECORDS.       21,102,505

CONTACT FOR QUERIES
              
NAME:          MRS C BRAY
TELEPHONE:     (01793) 567900



                    BLOCKLISTING SIX MONTHLY REVIEW


1. NAME OF COMPANY:    ISOTRON PLC



2. NAME OF SCHEME:     ISOTRON PLC SAYE SCHEME



3. PERIOD OF RETURN:     FROM:  1 JULY 2003     TO:  31 DECEMBER 2003



4. NUMBER AND CLASS OF SHARES(S)
   (AMOUNT OF STOCK/DEBT SECURITY)
   NOT ISSUED UNDER SCHEME
   AT END OF THE LAST PERIOD:         170,000



5. NUMBER OF SHARES ISSUED/ALLOTTED
   UNDER SCHEME DURING PERIOD:           -



6. BALANCE UNDER SCHEME NOT YET ISSUED/ALLOTTED 
   AT END OF PERIOD:    170,000



7. NUMBER AND CLASS OF SHARE(S)                    170,000 
   (AMOUNT OF STOCK/DEBT SECURITIES)               REF: ISOTRON PLC/
   ORIGINALLY LISTED AND THE DATE OF ADMISSION:    00001-00002
                                                   5 MARCH 1999


PLEASE CONFIRM TOTAL NUMBER OF SHARES IN ISSUE AT THE END OF THE PERIOD
IN ORDER FOR US TO UPDATE OUR RECORDS.       21,102,505

CONTACT FOR QUERIES

NAME:          MRS C BRAY
TELEPHONE:     (01793) 5679900



                    BLOCKLISTING SIX MONTHLY REVIEW


1. NAME OF COMPANY:     ISOTRON PLC



2. NAME OF SCHEME:      ISOTRON 1994 EXECUTIVE SHARE OPTION SCHEME



3. PERIOD OF RETURN:     FROM:  1 JULY 2003   TO:  31 DECEMBER 2003



4. NUMBER AND CLASS OF SHARES(S)
   (AMOUNT OF STOCK/DEBT SECURITY)
   NOT ISSUED UNDER SCHEME
   AT END OF THE LAST PERIOD:       500,000



5. NUMBER OF SHARES ISSUED/ALLOTTED
   UNDER SCHEME DURING PERIOD:        -



6. BALANCE UNDER SCHEME NOT YET ISSUED/ALLOTTED 
   AT END OF PERIOD:       500,000



7. NUMBER AND CLASS OF SHARE(S)                   500,000
   (AMOUNT OF STOCK/DEBT SECURITIES)              REF: (0-461-685)
   ORIGINALLY LISTED AND THE DATE OF ADMISSION:   (GB0004616859
                                                   21 MARCH 2003


PLEASE CONFIRM TOTAL NUMBER OF SHARES IN ISSUE AT THE END OF THE PERIOD
IN ORDER FOR US TO UPDATE OUR RECORDS.     21,102,505

CONTACT FOR QUERIES

NAME:           MRS C BRAY
TELEPHONE:      (01793)567900




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


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