<PAGE>   1

                                   EXHIBIT 99
                                   ----------





January 20, 1998



Dear Shareholders:

         The enclosed press release announces that Allen Telecom Inc. has
adopted a new share purchase rights plan to replace the Company's existing
rights plan, which expires on January 20, 1998.

         A summary of the share purchase rights plan (which explains the terms
and nature of the rights) is enclosed. Shareholders are urged to review the
summary carefully and retain it with their permanent records.

Sincerely,



Robert G. Paul
President and
  Chief Executive Officer







                                       

<PAGE>   2



                                                           FOR IMMEDIATE RELEASE
                                                           ---------------------

                      ALLEN TELECOM INC. ADOPTS REPLACEMENT
                      -------------------------------------
                           SHARE PURCHASE RIGHTS PLAN
                           --------------------------


         Beachwood, Ohio, January 5, 1998 - Allen Telecom Inc. (NYSE:ALN)
("Allen Telecom") announced today that its Board of Directors has adopted a
replacement share purchase rights plan that provides for rights to be issued to
stockholders of record on January 20, 1998. The new rights plan replaces Allen
Telecom's existing rights plan, which expires on that date.

         According to Robert G. Paul, President and Chief Executive Officer,
"This action was not taken in response to any pending takeover or proposed
change in control of the Company. Like the Company's existing rights plan, the
new rights plan is intended to protect the Company and its stockholders from
potentially coercive takeover practices or takeover bids which are inconsistent
with the interests of the Company and its stockholders. Share purchase rights
plans have become common in major American companies and are a well-accepted
approach to ensuring that all stockholders receive a fair price and are treated
equally in the event of a takeover."

         Under the plan, the rights will initially trade together with Allen
Telecom common stock and will not be exercisable. In the absence of further
action by Allen Telecom's Board of Directors, the rights generally will become
exercisable and allow the holder to acquire Allen Telecom common stock at a
discounted price if a person or group acquires 20 percent or more of the
outstanding shares of Allen Telecom common stock. Rights held by persons who
exceed the applicable threshold will be void. Under certain circumstances, the
rights will entitle the holder to buy shares in an acquiring entity at a
discounted price.

                                      2


<PAGE>   3


         The plan also includes an exchange option. In general, after the rights
become exercisable, in certain circumstances the Board of Directors may, at its
option and without requiring any payment, effect an exchange of part or all of
the rights - other than rights that have become void - for shares of Allen
Telecom common stock. Under this option, Allen Telecom would issue one share of
common stock for each right, subject to adjustment in certain circumstances.

         Allen Telecom's Board of Directors may, at its option, redeem all
rights for $.01 per right, generally at any time prior to the rights becoming
exercisable. The rights will expire January 20, 2008, unless earlier redeemed,
exchanged or amended by the Board of Directors.

         The issuance of the rights is not a taxable event, will not affect
Allen Telecom's reported financial condition or results of operations (including
earnings per share) and will not change the way in which Allen Telecom common
stock is currently traded.

         Statements included in this news releases which are not historical in
nature are forward-looking statements made pursuant to the safe harbor
provisions of the Private Securities Litigation Reform Act of 1995. Allen
Telecom's Annual Report on Form 10-K and Quarterly Reports on Form 10-Q contain
certain detailed factors that could cause Allen Telecom's actual results to
materially differ from forward-looking statements made by Allen Telecom,
including, among others, the costs and timetable for new product development,
the uncertain level of purchases by current and prospective customers of Allen
Telecom's products and services and the impact of competitive products and
pricing.

         Allen Telecom Inc. is a leading supplier to the worldwide two-way
wireless communications marketplace of systems expansion products, site
management products and antennas and provides frequency planning, system
engineering services and software design programs to current and emerging
wireless markets.

For further information contact:                    Robert A. Youdelman
                                                    216/765-5820
                                                    http://www.allentelecom.com
                                                    ---------------------------

                                      3


<PAGE>   4




                  SUMMARY OF RIGHTS TO PURCHASE PREFERRED STOCK

         The Board of Directors (the "Board") of Allen Telecom Inc. (the
"Company") has declared a dividend distribution of one right (a "Right") for
each outstanding share of Common Stock, par value $1.00 per share (the "Common
Shares"), of the Company. The distribution is payable on January 20, 1998 (the
"Record Date") to the stockholders of record as of the close of business on the
Record Date. Each Right entitles the registered holder thereof to purchase from
the Company one one-hundredth of a share of Series C Junior Participating
Preferred Stock, without par value (the "Preferred Shares"), of the Company at a
price (the "Purchase Price") of $100.00 per one one-hundredth of a Preferred
Share, subject to adjustment. The description and terms of the Rights are set
forth in a Rights Agreement, dated as of January 20, 1998 (the "Rights
Agreement"), between the Company and Harris Trust Company of New York, as Rights
Agent (the "Rights Agent").

         Under the Rights Agreement, the Rights will be evidenced by the
certificates evidencing Common Shares until the earlier (the "Distribution
Date") of: (i) the close of business on the first date (the "Share Acquisition
Date") of public announcement that a person (other than the Company, a
subsidiary or employee benefit or stock ownership plan of the Company or any of
its affiliates or associates), together with its affiliates and associates, has
acquired beneficial ownership of 20% or more of the outstanding Common Shares
(any such person being hereinafter called an "Acquiring Person") or (ii) the
close of business on the tenth business day (or such later date as may be
specified by the Board) following the commencement of a tender offer or exchange
offer by a person (other than the Company, a subsidiary or employee benefit or
stock ownership plan of the Company or any of its affiliates or associates), the
consummation of which would result in beneficial ownership by such person of 20%
or more of the outstanding Common Shares.

         The Rights Agreement provides that, until the Distribution Date, the
Rights may be transferred with and only with the Common Shares. Until the
Distribution Date (or earlier redemption or expiration of the Rights), any
certificate evidencing Common Shares of the Company issued upon transfer or new
issuance of the Common Shares will contain a notation incorporating the Rights
Agreement by reference. Until the Distribution Date (or earlier redemption or
expiration of the Rights), the surrender for transfer of any certificates
evidencing Common Shares will also constitute the transfer of the Rights
associated with such certificates. As soon as practicable following the
Distribution Date, separate certificates evidencing the Rights ("Right
Certificates") will be mailed to holders of record of Common Shares as of the
close of business on the Distribution Date and such separate Right Certificates
alone will evidence the Rights. No Right is exercisable at any time prior to the
Distribution Date. The Rights will expire on the tenth anniversary of the Record
Date (the "Final Expiration Date") unless earlier redeemed, exchanged or amended
by the Company as described below. Until a Right is exercised, the holder
thereof, as such, will have no rights as a stockholder of the Company, including
the right to vote or to receive dividends.

                                      4


<PAGE>   5



         The Purchase Price payable, and the number of the Preferred Shares or
other securities issuable, upon exercise of the Rights will be subject to
adjustment from time to time to prevent dilution (i) in the event of a stock
dividend on, or a subdivision, combination or reclassification of, the Preferred
Shares, (ii) upon the grant to holders of Preferred Shares of certain rights or
warrants to subscribe for or purchase the Preferred Shares at a price, or
securities convertible into the Preferred Shares with a conversion price, less
than the then-current market price of the Preferred Shares, or (iii) upon the
distribution to holders of the Preferred Shares of evidences of indebtedness,
cash (excluding regular periodic cash dividends), assets, stock (excluding
dividends payable in the Preferred Shares) or subscription rights or warrants
(other than those referred to above). The number of outstanding Rights and the
number of one one-hundredths of the Preferred Shares issuable upon exercise of
each Right will be subject to adjustment in the event of a stock dividend on the
Common Shares payable in Common Shares or a subdivision, combination or
reclassification of Common Shares occurring, in any such case, prior to the
Distribution Date.

         The Preferred Shares issuable upon exercise of the Rights will not be
redeemable. Each Preferred Share will be entitled, in connection with the
declaration of a dividend on the Common Shares, to a preferential dividend
payment equal to the greater of (i) $1.00 per share and (ii) an amount equal to
100 times the related dividend declared per Common Share. Subject to customary
anti-dilution provisions, in the event of liquidation, the holders of Preferred
Shares will be entitled to a preferential liquidation payment equal to the
greater of (a) $100 per share and (b) an amount equal to 100 times the
liquidation payment made per Common Share. Because of the nature of the
Preferred Shares' dividend, voting and liquidation rights, the value of the one
one-hundredth interest in a Preferred Share purchasable upon exercise of a Right
should approximate the value of one Common Share.

         Rights will be exercisable to purchase Preferred Shares only after the
Distribution Date occurs and prior to the occurrence of a Flip-in Event as
described below. A Distribution Date resulting from the commencement of a tender
offer or exchange offer described in clause (ii) of the second paragraph of this
summary could precede the occurrence of a Flip-in Event and thus result in the
Rights being exercisable to purchase Preferred Shares. A Distribution Date
resulting from any occurrence described in clause (i) of the second paragraph of
this summary would necessarily follow the occurrence of a Flip-in Event and thus
result in the Rights being exercisable to purchase Common Shares or other
securities as described below.

         Under the Rights Agreement, in the event (a "Flip-in Event") that any
person, together with its affiliates and associates, becomes the beneficial
owner of 20% or more of the outstanding Common Shares, then proper provision
will be made so that from and after the Share Acquisition Date each holder of a
Right, other than Rights that are or were owned beneficially by an Acquiring
Person (which, from and after the date of a Flip-in Event, will be void), will
have the right to receive, upon exercise thereof at the then-current exercise
price of the Right, that number of Common Shares (or, under certain
circumstances, an economically equivalent security or securities of the Company)
that on the Share Acquisition Date have a market value of two times the exercise
price of the Right.

                                      5


<PAGE>   6


         In the event (a "Flip-over Event") that, at any time after a person has
become an Acquiring Person, (i) the Company merges with or into any person and
the Company is not the surviving corporation, (ii) any person merges with or
into the Company and the Company is the surviving corporation, but all or part
of the Common Shares are changed or exchanged for stock or other securities of
any other person or cash or any other property, or (iii) 50% or more of the
Company's assets or earning power, including securities creating obligations of
the Company, are sold, in each case as described in the Rights Agreement, then,
in each such case, proper provision will be made so that from and after the
later of the Share Acquisition Date and the date of the occurrence of such
Flip-over Event each holder of a Right, other than Rights which have become
void, will have the right to receive, upon the exercise thereof at the
then-current exercise price of the Right, that number of shares of common stock
(or, under certain circumstances, an economically equivalent security or
securities) of such other person that at the time of such Flip-over Event have a
market value of two times the exercise price of the Right.

         From and after the Share Acquisition Date, Rights (other than any
Rights that have become void) will be exercisable as described above, upon
payment of the aggregate exercise price in cash. In addition, at any time after
the Share Acquisition Date and prior to the acquisition by any person or group
of affiliated or associated persons of 50% or more of the outstanding Common
Shares, the Company may exchange the Rights (other than any rights that have
become void), in whole or in part, without requiring payment, at an exchange
ratio of one Common Share per Right (subject to adjustment).

         With certain exceptions, no adjustment in the Purchase Price will be
required until cumulative adjustments require an adjustment in the Purchase
Price of at least 1%. The Company will not be required to issue fractional
Preferred Shares (other than fractions that are integral multiples of one
one-hundredth of a Preferred Share, which may, at the option of the Company, be
evidenced by depositary receipts) or fractional Common Shares or other
securities issuable upon the exercise of Rights. In lieu of issuing such
securities, the Company may make a cash payment, as provided in the Rights
Agreement.

         The Company may, at its option, redeem the Rights in whole, but not in
part, at a price of $.01 per Right, subject to adjustment (the "Redemption
Price"), at any time prior to the close of business on the Share Acquisition
Date. Immediately upon any redemption of the Rights, the right to exercise the
Rights will terminate and the only right of the holders of Rights will be to
receive the Redemption Price.

         The Rights Agreement may be amended by the Company without the approval
of any holders of Right Certificates, including amendments that increase or
decrease the Purchase Price, that add other events requiring adjustment to the
Purchase Price payable and the number of the Preferred Shares or other
securities issuable upon the exercise of the Rights or that modify procedures
relating to the redemption of the Rights, except that no amendment may be made
that decreases the stated Redemption Price to an amount less than $.01 per
Right.

                                      6


<PAGE>   7




         The Board will have the exclusive power and authority to administer the
Rights Agreement and to exercise all rights and powers specifically granted to
the Board or to the Company therein, or as may be necessary or advisable in the
administration of the Rights Agreement, including without limitation the right
and power to interpret the provisions of the Rights Agreement and to make all
determinations deemed necessary or advisable for the administration of the
Rights Agreement (including any determination to redeem or not redeem the Rights
or to amend or not amend the Rights Agreement). All such actions, calculations,
interpretations and determinations (including any omission with respect to any
of the foregoing) which are done or made by the Board in good faith will be
final, conclusive and binding on the Company, the Rights Agent, the holders of
the Rights and all other parties and will not subject the Board to any liability
to any person, including without limitation the Rights Agent and the holders of
the Rights.

         A copy of the Rights Agreement has been filed with the Securities and
Exchange Commission as an exhibit to a Registration Statement on Form 8-A. A
copy of the Rights Agreement is available free of charge from the Company.

         This summary description of the Rights is as of the Record Date, does
not purport to be complete and is qualified in its entirety by reference to the
Rights Agreement, which is incorporated herein by this reference.

                                      7