SECURITIES AND EXCHANGE COMMISSION
                             Washington, D. C. 20549
                                  SCHEDULE l3D
                                (Amendment No. 1)
                    Under the Securities Exchange Act of 1934

                                   OCTEL CORP.
- --------------------------------------------------------------------------------
                                (Name of Issuer)

                     Common Stock, par value $0.01 per share
- --------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    67572710
- --------------------------------------------------------------------------------
                                 (CUSIP Number)
                                                    with a copy to:
Jeffrey S. Halis                                    Laura R. Kuntz, Esq.
500 Park Avenue                                     LOWENSTEIN SANDLER PC
Fifth Floor                                         65 Livingston Avenue
New York, New York  10022                           Roseland, New Jersey  07068
(212) 378-0879                                     (973) 597-2500

- --------------------------------------------------------------------------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                  June 3, 1998
- --------------------------------------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously  filed a statement on Schedule l3G to report
the  acquisition  which is the subject of this  Schedule 13D, and is filing this
schedule because of Rule 13d-1(b)(3) or (4), check the following box. |_|

Note: Six copies of this statement, including all exhibits, should be filed with
the  Commission.  See Rule  l3d-1(a) for other  parties to whom copies are to be
sent.

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

- --------------------------------------------------------------------------------
 1) Names of Reporting Persons (S.S. or I.R.S. Identification Nos. of Above 
    Persons):

                                Jeffrey S. Halis

2)  Check the Appropriate Box if a Member of a Group (See Instructions):
         (a)                                Not
         (b)                             Applicable

3)  SEC Use Only

4)  Source of Funds (See Instructions):  WC

5) Check if Disclosure  of Legal  Proceedings  is Required  Pursuant to Items 
   2(d) or 2(e):

                                    Not Applicable

6) Citizenship or Place of Organization:

                                  United States

    Number of                    7) Sole Voting Power:                1,263,400*
                                    --------------------------------------------
    Shares Beneficially          8) Shared Voting Power:                      0
                                    --------------------------------------------
    Owned by
    Each Reporting               9) Sole Dispositive Power:           1,263,400*
                                    --------------------------------------------
    Person With:                10) Shared Dispositive Power:                 0
                                    -------------------------------------------

11)   Aggregate Amount Beneficially Owned by Each Reporting Person:

                  1,263,400*

12)  Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See 
     Instructions):
    
                                      Not Applicable

13)  Percent of Class Represented by Amount in Row (11):      8.6%*

14)  Type of Reporting Person (See Instructions):       IA

*    851,100  shares  (5.8%) of Octel  Corp.  common  stock are owned by Tyndall
     Partners,  L.P., a Delaware limited  partnership.  136,200 shares (0.9%) of
     Octel Corp. common stock are owned by Tyndall Institutional Partners, L.P.,
     a Delaware limited partnership.  82,900 shares (0.6%) of Octel Corp. common
     stock are owned by  Madison  Avenue  Partners,  L.P.,  a  Delaware  limited
     partnership. 193,200 shares (1.3%) of Octel Corp. common stock are owned by
     Halo International,  Ltd., a company organized under the laws of the Cayman
     Islands.  Pursuant  to the  Agreement  of  Limited  Partnership  of each of
     Tyndall Partners,  L.P., Tyndall Institutional Partners,  L.P., and Madison
     Avenue  Partners,  L.P.  and the  Investment  Management  Agreement of Halo
     International,  Ltd., Jeffrey S. Halis possesses sole voting and investment
     control  over all  securities  owned  by each of  Tyndall  Partners,  L.P.,
     Tyndall Institutional  Partners,  L.P., Madison Avenue Partners,  L.P., and
     Halo International,  Ltd., respectively. See Item 5 for further information
     on the computation of percentages set forth herein.

Item 5.   Interest in Securities of the Issuer.

          Based upon  information  set forth in Octel Corp.'s Form 10 filed with
the  Securities  and Exchange  Commission on May 4, 1998,  there are  14,736,075
shares of Octel Corp.  common stock issued and outstanding.  As of June 8, 1998,
Tyndall  Partners,  L.P.  owned  851,100  of  such  shares,  or  5.8%  of  those
outstanding,  Tyndall Institutional Partners, L.P. owned 136,200 of such shares,
or 0.9% of those outstanding, Madison Avenue Partners, L.P. owned 82,900 of such
shares, or 0.6% of those outstanding, and Halo International, Ltd. owned 193,200
of such shares, or 1.3% of those outstanding. Jeffrey Halis possesses sole power
to vote and direct the  disposition of all shares of common stock of Octel Corp.
owned by each of Tyndall Partners,  L.P., Tyndall Institutional Partners,  L.P.,
Madison Avenue Partners, L.P., and Halo International,  Ltd. The following table
details  the   transactions  by  each  of  Tyndall   Partners,   L.P.,   Tyndall
Institutional   Partners,   L.P.,  Madison  Avenue  Partners,   L.P.,  and  Halo
International,  Ltd.  in shares of common  stock of Octel  Corp.  since the most
recent filing on Schedule 13D (each of which were  effected in ordinary  brokers
transactions):

                            A. Tyndall Partners, L.P.

         Date                       Quantity                          Price

                                   (Purchases)

    May 29, 1998                     44,000                           $21.96
    June 2, 1998                     27,100                            19.97
    June 3, 1998                     36,900                            20.47
    June 5, 1998                     30,000                            20.03
    June 8, 1998                     28,000                            20.28

                                     (Sales)

                                      NONE

                     B. Tyndall Institutional Partners, L.P.

         Date                       Quantity                          Price

                                   (Purchases)

    May 29, 1998                      7,600                           $21.96
    June 2, 1998                      4,600                            19.97
    June 3, 1998                      6,300                            20.47

                                     (Sales)

                                      NONE

                        C. Madison Avenue Partners, L.P.

         Date                       Quantity                          Price

                                   (Purchases)

    May 29, 1998                      4,500                           $21.96
    June 2, 1998                      2,900                            19.97
    June 3, 1998                      3,800                            20.47

                                     (Sales)

                                      NONE

                           D. Halo International, Ltd.

         Date                       Quantity                          Price

                                   (Purchases)

    May 29, 1998                     8,900                            $21.96
    June 2, 1998                     5,400                             19.97
    June 3, 1998                     7,400                             20.47
    June 5, 1998                    20,000                             20.03
    June 8, 1998                    14,000                             20.28

                                     (Sales)

                                      NONE

                                    Signature

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

                                                              June 10, 1998

                                                         /s/Jeffrey S. Halis
                                                         Jeffrey S.  Halis, as  
                                                         a  general  partner  of
                                                         Halo Capital  Partners,
                                                         L.P.,    the    general
                                                         partner   of   each  of
                                                         Tyndall Partners, L.P.,
                                                         Tyndall  Institutional 
                                                         Partners,  L.P.,   and 
                                                         Madison Avenue Partners
                                                         L.P.

                                                         /s/Jeffrey S. Halis
                                                         Jeffrey S.  Halis,   as
                                                         a   member  of   Jemi  
                                                         Management,   L.L.C.,  
                                                         the Investment  Manager
                                                         for Halo International,
                                                         Ltd.

ATTENTION:  INTENTIONAL  MISSTATEMENTS  OR OMISSIONS OF FACT CONSTITUTE  FEDERAL
CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001).