<PAGE>
EXHIBIT 99(a)(7)
This announcement is neither an offer to purchase nor a solicitation of an offer
to sell Shares (as defined below). The Offer (as defined below) is being made
solely by the Offer to Purchase, dated September 8, 2000, and the related Letter
of Transmittal, and is being made to all holders of Shares. Purchaser (as
defined below) is not aware of any state where the making of the Offer is
prohibited by any administrative or judicial action pursuant to any valid state
statute. If Purchaser becomes aware of any valid state statute prohibiting the
making of the Offer or the acceptance of the Shares pursuant thereto, Purchaser
will make a good faith effort to comply with such state statute. If, after such
good faith effort, Purchaser cannot comply with such state statute, the Offer
will not be made to (nor will tenders be accepted from or on behalf of) holders
of Shares in such state. In any jurisdiction where the securities, blue sky or
other laws require the Offer to be made by a licensed broker or dealer, the
Offer shall be deemed to be made on behalf of Purchaser by Credit Suisse First
Boston Corporation ("Credit Suisse First Boston" or the "Dealer Manager") or one
or more registered brokers or dealers licensed under the laws of such
jurisdiction.
Notice of Offer to Purchase for Cash
All Outstanding Shares of Common Stock
of the Series Designated
Donaldson, Lufkin & Jenrette, Inc. - DLJ Common Stock
of
Donaldson, Lufkin & Jenrette, Inc.
at
$90.00 Net Per Share
by
Diamond Acquisition Corp.
An indirect wholly owned subsidiary of
Credit Suisse Group
Diamond Acquisition Corp., a Delaware corporation ("Purchaser") and an indirect
wholly owned subsidiary of Credit Suisse Group, a corporation organized under
the laws of Switzerland ("Parent"), is offering to purchase all the issued and
outstanding shares of common stock of the series designated Donaldson, Lufkin &
Jenrette, Inc. - DLJ Common Stock, par value $.10 per share (the "Shares"), of
Donaldson, Lufkin & Jenrette, Inc., a Delaware corporation (the "Company"), for
$90.00 per Share, net to the
<PAGE>
seller in cash, upon the terms and subject to the conditions set forth in the
Offer to Purchase, dated September 8, 2000 (the "Offer to Purchase"), and in the
related Letter of Transmittal (which, together with the Offer to Purchase and
any amendments or supplements thereto, collectively constitute the "Offer").
Following the purchase of Shares pursuant to the Offer, Purchaser intends to
effect the Merger described below.
THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
TIME, ON THURSDAY, OCTOBER 5, 2000, UNLESS THE OFFER IS EXTENDED.
The Offer is conditioned upon, among other things, any applicable waiting period
under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended,
having expired or been terminated and receipt of the requisite approval of the
Commission of the European Union under the EC Merger Regulation prior to the
expiration of the Offer. The Offer is being made pursuant to an Agreement and
Plan of Merger, dated as of August 30, 2000 (the "Merger Agreement"), among
Parent, Purchaser and the Company. The Merger Agreement provides, among other
things, that as promptly as practicable after the purchase of Shares pursuant to
the Offer, the purchase of Shares held by certain stockholders pursuant to a
Stock Purchase Agreement, dated as of August 30, 2000, among Credit Suisse
Group, AXA, AXA Financial, Inc., The Equitable Life Assurance Society of the
United States and AXA Participations Belgium and the satisfaction or, if
permissible, waiver of the other conditions set forth in the Merger Agreement
and in accordance with the relevant provisions of the Delaware General
Corporation Law ("Delaware Law"), Purchaser will be merged with and into the
Company (the "Merger"). As a result of the Merger, the Company will continue as
the surviving corporation (the "Surviving Corporation") and will become an
indirect subsidiary of Parent. At the effective time of the Merger (the
"Effective Time") and without any action on the part of the holder thereof, each
Share issued and outstanding immediately prior to the Effective Time (other than
Shares held in the treasury of the Company or Shares held by Parent, Purchaser
or any wholly owned subsidiary of Parent or of the Company, and other than
Shares held by stockholders who shall have demanded and perfected appraisal
rights under Delaware Law) will be converted into the right to receive $90.00
net in cash, or any higher price that may be paid per Share in the Offer,
without interest.
The Board of Directors of the Company has unanimously determined that the
Merger Agreement and the transactions contemplated thereby, including each of
the Offer and the Merger, are fair to, and in the best interests of, the
holders of Shares, approved, adopted and declared advisable the Merger
Agreement and the transactions contemplated thereby, and resolved to
recommend that the holders of Shares accept the Offer and tender their Shares
pursuant to the Offer and approve and adopt the Merger Agreement and the
transactions contemplated thereby.
For purposes of the Offer, Purchaser will be deemed to have accepted for
payment (and thereby purchased) Shares validly tendered and not properly
withdrawn as, if and
<PAGE>
when Purchaser gives oral or written notice to First Chicago Trust Company of
New York (the "Depositary") of Purchaser's acceptance for payment of such Shares
pursuant to the Offer. Upon the terms and subject to the conditions of the
Offer, payment for Shares accepted for payment pursuant to the Offer will be
made by deposit of the purchase price therefor with the Depositary, which will
act as agent for tendering stockholders for the purpose of receiving payments
from Purchaser and transmitting such payments to tendering stockholders whose
Shares have been accepted for payment. Under no circumstances will interest on
the purchase price for Shares be paid, regardless of any delay in making such
payment. In all cases, payment for Shares tendered and accepted for payment
pursuant to the Offer will be made only after timely receipt by the Depositary
of (i) the certificates evidencing such Shares (the "Share Certificates") or
timely confirmation of a book-entry transfer of such Shares into the
Depositary's account at the Book-Entry Transfer Facility (as defined in Section
2 of the Offer to Purchase) pursuant to the procedure set forth in Section 3 of
the Offer to Purchase, (ii) the Letter of Transmittal (or a manually signed
facsimile thereof), properly completed and duly executed, with any required
signature guarantees or an Agent's Message (as defined in Section 2 of the Offer
to Purchase) and (iii) any other documents required under the Letter of
Transmittal.
Purchaser expressly reserves the right, in its sole discretion (but subject
to the terms and conditions of the Merger Agreement), at any time and from
time to time, to extend for any reason the period of time during which the
Offer is open, including the occurrence of any condition specified in Section
14 of the Offer to Purchase, by giving oral or written notice of such
extension to the Depositary. Any such extension will be followed as promptly
as practicable by public announcement thereof, such announcement to be made
no later than 9:00 a.m., New York City time, on the next business day after
the previously scheduled expiration date of the Offer. During any such
extension, all Shares previously tendered and not withdrawn will remain
subject to the Offer and subject to the right of a tendering stockholder to
withdraw such stockholder's Shares.
Shares may be withdrawn at any time prior to 12:00 Midnight, New York City
time, on Thursday, October 5, 2000 (or the latest time and date at which the
Offer, if extended by Purchaser, shall expire). For the withdrawal to be
effective, a written or facsimile transmission notice of withdrawal must be
timely received by the Depositary at one of its addresses set forth on the
back cover page of the Offer to Purchase. Any such notice of withdrawal must
specify the name of the person who tendered the Shares to be withdrawn, the
number of Shares to be withdrawn and the name of the registered holder of
such Shares, if different from that of the person who tendered such Shares.
If Share Certificates evidencing Shares to be withdrawn have been delivered
or otherwise identified to the Depositary, then, prior to the physical
release of such Share Certificates, the serial numbers shown on such Share
Certificates must be submitted to the Depositary and the signature(s) on the
notice of withdrawal must be guaranteed by an Eligible Institution (as
defined in Section 3 of the Offer to Purchase), unless such Shares have been
tendered for the account of an Eligible Institution. If Shares have been
tendered pursuant to the procedure for book-entry transfer as set forth in
Section 3 of the Offer to Purchase, any notice of withdrawal must specify the
name and number
<PAGE>
of the account at the Book-Entry Transfer Facility to be credited with the
withdrawn Shares. All questions as to the form and validity (including the time
of receipt) of any notice of withdrawal will be determined by Purchaser, in its
sole discretion, which determination will be final and binding.
The information required to be disclosed by Rule 14d-6(d)(1) of the General
Rules and Regulations under the Securities Exchange Act of 1934, as amended,
is contained in the Offer to Purchase and is incorporated herein by reference.
The Company has provided Purchaser with the Company's stockholder list and
security position listings, including the most recent list of names,
addresses and security positions of non-objecting beneficial owners in the
possession of the Company, for the purpose of disseminating the Offer to
holders of Shares. The Offer to Purchase and the related Letter of
Transmittal will be mailed to record holders of Shares whose names appear on
the Company's stockholder lists and will be furnished, for subsequent
transmittal to beneficial owners of Shares, to brokers, dealers, commercial
banks, trust companies and similar persons whose names, or the names of whose
nominees, appear on the stockholder list or, if applicable, who are listed as
participants in a clearing agency's security position listing.
The Offer to Purchase and the related Letter of Transmittal contain important
information which should be read before any decision is made with respect to
the Offer. Questions and requests for assistance or for additional copies of
the Offer to Purchase and the related Letter of Transmittal and other tender
offer materials may be directed to the Information Agent or the Dealer
Manager as set forth below, and copies will be furnished promptly at
Purchaser's expense. No fees or commissions will be paid to brokers, dealers
or other persons (other than the Information Agent, the Dealer Manager and
the Depositary) for soliciting tenders of Shares pursuant to the Offer.
The Information Agent for the Offer is:
D. F. KING & CO., INC.
77 Water Street
New York, New York 10005
Bankers and Brokers Call Collect: (212) 425-1685
All Others Call Toll Free: (800) 628-8536
The Dealer Manager for the Offer is:
CREDIT SUISSE FIRST BOSTON LOGO
Eleven Madison Avenue
New York, New York 10010-3629
Call toll free (800) 881-8320
September 8, 2000