SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                  SCHEDULE 13G


             INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934


                          West Pharmaceutical Services
                          ----------------------------
                                (Name of Issuer)


                                     Common
                                     ------
                         (Title of Class of Securities)


                                    955306105
                                    ---------
                                 (CUSIP Number)



                                Page 1 of 5 Pages



<PAGE>

                                                                    SCHEDULE 13G

CUSIP No. 955306105
--------------------------------------------------------------------------------
1)       NAME OF REPORTING PERSON
         S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

         Lazard Freres & Co. LLC
--------------------------------------------------------------------------------
2)       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP  
                                                         (a)   [ ]
                                                         (b)   [ ]
--------------------------------------------------------------------------------
3)       SEC USE ONLY

--------------------------------------------------------------------------------
4)       CITIZENSHIP OR PLACE OF ORGANIZATION
         New York
--------------------------------------------------------------------------------
                               5)   SOLE VOTING POWER
            NUMBER                  899,596                                
              OF            ----------------------------------------------------
            SHARES             6)   SHARED VOTING POWER
          BENEFICIALLY              None                                      
           OWNED BY         ----------------------------------------------------
             EACH              7)   SOLE DISPOSITIVE POWER
           REPORTING                1,138,904                              
            PERSON          ----------------------------------------------------
             WITH              8)   SHARED DISPOSITIVE POWER
                                    None
--------------------------------------------------------------------------------
9)       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         1,138,904                                                 
--------------------------------------------------------------------------------
10)      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES 
         CERTAIN SHARES                                              [ ]
--------------------------------------------------------------------------------
11)      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
         7.63%                                            
--------------------------------------------------------------------------------
12)      TYPE OF REPORTING PERSON
         IA    
--------------------------------------------------------------------------------


<PAGE>

                                  Schedule 13G

Item 1(a).   Name of Issuer:

West Pharmaceutical Services

Item 1(b).   Address of Issuer's Principal Executive Offices:

101 Gordon Drive
P.O. Box 645
Lionville, PA 19341-0645

Item 2(a).   Name of Person Filing:

Lazard Freres & Co. LLC

Item 2(b).   Address of Principal Business Office or, if None, Residence:

30 Rockefeller Plaza
New York, New York  10020

Item 2(c).   Citizenship:

New York Limited Liability Company

Item 2(d).   Title of Class of Securities:

Common Stock

Item 2(e).   CUSIP Number: 955306105

Item 3.      If this  statement  is  filed  pursuant  to Rules  13d-1(b),  or
             13d-2(b), check whether the person filing is a:

             [ ]   (a)  Broker or Dealer Registered Under Section 15 of the Act

             [x]   (e)  Investment  Adviser  registered under section 203 of the
                        Investment Advisers Act of 1940

Item 4.      Ownership.

             (a)  Amount beneficially owned:     1,138,904

             (b)  percent of class:   7.63%

             (c)  Number of shares as to which such person has:



<PAGE>

             (i)   Sole power to vote or to direct the vote:       899,596

             (ii)  Shared power to vote or to direct the vote:  None

             (iii) Sole power to dispose or to direct the disposition of: 
                   1,138,904

             (iv)  Shared power to dispose or to direct the disposition of:
                   None

Item 5.      Ownership of Five Percent or Less of a Class.

             Not applicable

Item 6.      Ownership of More than Five Percent on Behalf of Another Person.

             Clients of the Reporting Person have the right to receive dividends
and  proceeds  of sale of the  securities  reported  on  this  Schedule.  To the
knowledge of the Reporting  Person,  no such person has an interest  relating to
more than five percent of the class of such securities.

Item 7.      Identification  and Classification of the Subsidiary Which Acquired
             the Security Being Reported on by the Parent Holding Company.

             Not applicable

Item 8.      Identification and Classification of Members of the Group.

             Not applicable

Item 9.      Notice of Dissolution of Group.

             Not applicable

Item 10.     Certification.

             By signing  below I certify  that,  to the best of my knowledge and
belief, the securities referred to above were acquired in the ordinary course of
business  and were not acquired for the purpose of and do not have the effect of
changing or  influencing  the control of the issuer of such  securities and were
not acquired in connection  with or as a participant in any  transaction  having
such purposes or effect.



<PAGE>

                                    SIGNATURE


             After  reasonable  inquiry and to the best  knowledge and belief of
the  undersigned,  the  undersigned  certifies that the information set forth in
this Statement is true, complete and correct.


Date:    February 3, 2000


                                                     /s/ Sr. Donald E. Klein
                                                     -------------------------
                                                     Sr. Donald E. Klein
                                                     Vice President