SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER

                      Pursuant to Rule 13a-16 or 15d-16 of
                      the Securities Exchange Act of 1934

                         For the month of October, 2005

                       PRUDENTIAL PUBLIC LIMITED COMPANY

                (Translation of registrant's name into English)

                            LAURENCE POUNTNEY HILL,
                           LONDON, EC4R 0HH, ENGLAND
                    (Address of principal executive offices)


Indicate by check mark whether the registrant files or will file annual reports 
under cover Form 20-F or Form 40-F. 

                          Form 20-F X     Form 40-F


Indicate by check mark whether the registrant by furnishing the information 
contained in this Form is also thereby furnishing the information to the 
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

                                 Yes      No X

If "Yes" is marked, indicate below the file number assigned to the registrant 
in connection with Rule 12g3-2(b): 82-             



Enclosure: Rule 2.10 Announcement



Prudential plc

31 October 2005

For Immediate Release



Prudential plc ("Prudential")

Rule 2.10 announcement - Update of Relevant Securities in Issue

In accordance with Rule 2.10 of the City Code on Takeovers and Mergers,
Prudential confirms that since its previous announcement under Rule 2.10 the
number of ordinary shares of 5p under option has decreased to 13,685,783. Part
of the ordinary shares under option may be satisfied by the transfer of existing
shares.

The International Securities Identification Number for Prudential's ordinary
shares is GB0007099541.



Additional information:

Prudential plc is not affiliated in any manner with Prudential Financial, Inc, a
company whose principal place of business is in the United States of America



Contact name for Enquiries


Sylvia Edwards

020 7548 3826



Company official responsible for making notification



Andrew Nash, Deputy Group Secretary

020 7548 3805

END

                                   SIGNATURES


Pursuant to the requirements of the Securities Exchange Act of 1934, the 
registrant has duly caused this report to be signed on its behalf by the 
undersigned, thereunto duly authorized. 

Date 31 October, 2005

                                     PRUDENTIAL PUBLIC LIMITED COMPANY 

                                     By: /s/  Andrew Nash, 

                                              Andrew Nash, 
                                              Deputy Group Secretary