<PAGE>
FILED PURSUANT TO RULE 424(b)(3)
REGISTRATION NO. 333-23355
SUPPLEMENT NO. 9, DATED JUNE 1, 1998
TO PROSPECTUS DATED JUNE 13, 1997
RELATING TO $98,000,000 PRINCIPAL AMOUNT
6% CONVERTIBLE SUBORDINATED NOTES DUE 2003 AND
4,286,964 SHARES OF COMMON STOCK, $0.01 PAR VALUE PER SHARE, OF
OFFSHORE LOGISTICS, INC.
All capitalized terms used but not defined herein shall have the meanings
prescribed in the Prospectus dated June 13, 1997, forming a part of the
Registration Statement on Form S-3, File No. 333-23355. Any cross references in
this Supplement refer to portions of the Prospectus.
The purpose of this supplement is to provide additional information regarding
the Selling Securityholders. In addition to the Selling Securityholders named
in the Prospectus or any previously filed Supplement thereto, the following
table sets forth the name of an additional Selling Securityholder and
relationship, if any, with the Company and (i) the amount of Notes owned by such
additional Selling Securityholder as of June 1, 1998 (subject to the
qualification set forth below), (ii) the maximum amount of Notes which may be
offered for the account of such Selling Securityholder as of June 1, 1998 and
(iii) the maximum amount of Common Stock which may be offered for the account of
such Selling Securityholder under the Prospectus.
<TABLE>
<CAPTION>
PRINCIPAL
PRINCIPAL AMOUNT OF COMMON STOCK COMMON STOCK
NAME OF SELLING AMOUNT OF NOTES OFFERED OWNED PRIOR TO OFFERED
SECURITYHOLDER NOTES OWNED HEREBY OFFERING (1) HEREBY (2)
<S> <C> <C> <C> <C>
Donaldson, Lufkin & Jenrette
Securities Corporation $1,500,000 $1,500,000 65,616 65,616
---------- ---------- ------ ------
TOTAL $1,500,000 $1,500,000 65,616 65,616
========== ========== ====== ======
</TABLE>
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(1) Comprises the shares of Common Stock into which the Notes held by such
Selling Securityholder are convertible at the initial conversion rate. The
Conversion Price and the number of shares of Common Stock issuable upon
conversion of the Notes are subject to adjustment under certain
circumstances. See "Description of Notes--Conversion Rights." Accordingly,
the number of shares of Common Stock issuable upon conversion of the Notes
may increase or decrease from time to time.
(2) Assumes conversion into Common Stock of the full amount of Notes held by the
Selling Securityholder at the initial conversion price and the offering of
such shares by such Selling Securityholder pursuant to the Registration
Statement of which the Prospectus forms a part. The Conversion Price and the
number of shares of Common Stock issuable upon conversion of the Notes are
subject to adjustment under certain circumstances. See "Description of
Notes--Conversion Rights." Accordingly, the number of shares of Common Stock
issuable upon conversion of the Notes may increase or decrease from time to
time. Fractional shares will not be issued upon conversion of the Notes;
rather, cash will be paid in lieu of fractional shares, if any.
Because the Selling Securityholders may, pursuant to this Prospectus, offer
all or some portion of the Notes they presently hold, no estimate can be given
as to the amount of the Notes that will be held by the Selling Securityholders
upon termination of any such sales. In addition, the Selling Securityholder
identified above may have sold, transferred or otherwise disposed of all or a
portion of their Notes since the date on which it provided the information
regarding their Notes, in transactions exempt from the registration requirements
of the Securities Act. See "Plan of Distribution."
The Company may from time to time, in accordance with the Registration Rights
Agreement, include additional Selling Securityholders in future supplements to
the Prospectus.