<PAGE>

                                                                   EXHIBIT 10.1

                  Exchange and Registration Rights Agreement


     Exchange and Registration Rights Agreement (this "Agreement") dated as of
                                                       ---------
April 9, 1999 among ARCH COMMUNICATIONS, INC., a Delaware corporation (the
"Company"), ARCH ESCROW CORP., a Delaware corporation (the "Issuer"), Bear,
 -------
Stearns & Co. Inc., TD Securities (USA) Inc., BNY Capital Markets, Inc., RBC
Dominion Securities Corporation and Barclays Capital Inc. (with Bear, Stearns &
Co. Inc., TD Securities (USA) Inc., BNY Capital Markets, Inc., RBC Dominion
Securities Corporation and Barclays Capital Inc. being referred to collectively
as, the "Initial Purchasers").
         ------------------

     This Agreement is made pursuant to the Purchase Agreement, dated as of
April 6, 1999 (the "Purchase Agreement"), among the Company, the Issuer and the
                    ------------------
Initial Purchasers, pursuant to which the Initial Purchasers have agreed,
severally and not jointly, to purchase from the Issuer $147,000,000 aggregate
principal amount of the Company's 13 3/4% Senior Notes due 2008 (the "Notes").
                                                                      -----
The Notes will be issued pursuant to an Indenture (the "Indenture") to be dated
                                                        ---------
as of the date hereof between the Issuer and IBJ Whitehall Bank & Trust Company,
as trustee (the "Trustee").  In connection with the consummation of the merger
                 -------
of the Issuer and the Company (the "Escrow Merger"), with the Company as the
                                    -------------
surviving corporation of the merger, described in the final Offering Memorandum
dated April 6, 1999, the Company will assume the obligations of the Issuer under
the Notes, the Indenture and this Agreement.  References to the Obligor refer to
(x) prior to the Escrow Merger, the Issuer, and (y) after the Escrow Merger, the
Company.  As an inducement to the Initial Purchasers to purchase the Notes, the
Obligor agrees with the Initial Purchasers, for the benefit of the holders of
the Notes and the Registered Notes (as defined), as follows:

     Section 1.  Certain Defined Terms.
                 ---------------------

          (a) As used in this Agreement, the following capitalized terms shall
have the following meanings:

          "Broker-Dealer" means any broker or dealer registered under the
           -------------
     Exchange Act.

          "Business Day" means any day other than a Saturday, a Sunday or a day
           ------------
     on which the banking institutions in the State of New York are authorized
     or obligated by law or executive order to close.

          "Commission" means the United States Securities and Exchange
           ----------
     Commission.

          "Consummate" means, with respect to a Registered Exchange Offer:  (i)
           ----------
     the filing and declaration of effectiveness under the Securities Act of the
     Exchange Offer Registration Statement relating to the Registered Notes to
     be issued in the Registered Exchange Offer; (ii) maintaining the continuous
     effectiveness of such Exchange Offer Registration Statement and keeping the
     Registered Exchange Offer open for a period of not less than 20 Business
     Days after the date of the mailing of the Prospectus pursuant to Section
     2(d)(i) hereof; and (iii) the delivery by the Obligor to the Registrar
     under the Indenture of the Registered Notes in the same aggregate principal
     amount as the aggregate principal amount of the Notes that were duly
     tendered by Holders
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     thereof pursuant to the Registered Exchange Offer, and
     "Consummated" or "Consummation" shall have a correlative meaning.
      -----------      ------------

          "Exchange Act" means the United States Securities Exchange Act of
           ------------
     1934, as amended, and the rules and regulations promulgated thereunder.

          "Exchange Offer Registration Statement" means a registration statement
           -------------------------------------
     (together with the Prospectus included therein, all amendments and
     supplements thereto (including post-effective amendments) and all exhibits
     and materials incorporated by reference therein) with respect to the
     Registered Exchange Offer.

          "Holder" means any Person who is the registered or beneficial owner of
           ------
     the Notes or the Registered Notes, as the case may be.

          "Escrow Merger Effective Date" shall mean the effective date of the
           ----------------------------
     Escrow Merger.

          "Person" means an individual, partnership, corporation, joint stock
           ------
     company, joint venture, trust, unincorporated organization or a government,
     agency or political subdivision thereof, firm or other entity.

          "Prospectus" means the prospectus included in any Registration
           ----------
     Statement, as amended or supplemented, including, without limitation, by
     any post-effective amendments thereto, and all material incorporated by
     reference into such prospectus.

          "Registration Statement" means the Exchange Offer Registration
           ----------------------
     Statement or the Shelf Registration Statement, as the context requires.

          "Securities Act" means the United States Securities Act of 1933, as
           --------------
     amended, and the rules and regulations promulgated thereunder.

          "Shelf Registration Statement" means a registration statement filed
           ----------------------------
     for a delayed or continuous period pursuant to Rule 415 or any similar rule
     that may be adopted by the Commission under the Securities Act (together
     with the Prospectus included therein, all amendments and supplements
     thereto (including post-effective amendments) and all exhibits and
     materials incorporated by reference therein) with respect to a Shelf
     Registration.

          "TIA" means the United States Trust Indenture Act of 1939, as amended,
           ---
     in effect on the date of the Indenture.

          "Transfer Restricted Securities" means each Note and each Registered
           ------------------------------
     Note, the Holder of which is subject to prospectus delivery requirements of
     the Securities Act in order to sell such Note or Registered Note, until the
     occurrence of any of the following events:

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               (i)     the first date on which such Note may be exchanged for a
          Registered Note in the Registered Exchange Offer, if following such
          exchange such Holder would be entitled to resell such Registered Note
          to the public without complying with the prospectus delivery
          requirements of the Securities Act;

               (ii)    the date on which such Note has been registered pursuant
          to an effective Shelf Registration Statement under the Securities Act
          and disposed of in accordance with the "Plan of Distribution" section
          of the Prospectus contained in such Shelf Registration Statement;

               (iii)   the date on which such Note is sold to the public
          pursuant to Rule 144 under the Securities Act or by a Broker-Dealer
          pursuant to the "Plan of Distribution" contemplated by the Exchange
          Offer Registration Statement (including delivery of the Prospectus
          contained therein); or

               (iv)    such Note or Registered Note, as the case may be, shall
          have ceased to be outstanding.

          (b)  Each of the following terms is defined in the Section set forth
     opposite such term:

               Term                           Section
               ----                           -------

               Agreement                      Preamble
               Company                        Preamble
               Indemnified Holder             7(a)
               Indenture                      Preamble
               Initial Purchasers             Preamble
               Issuer                         Preamble
               Liquidated Damages             8
               Losses                         7(a)
               Notes                          Preamble
               Obligor                        Preamble
               Participating Broker-Dealer    4(a)
               Purchase Agreement             Preamble
               Registered Exchange Offer      2(a)
               Registered Notes               2(a)
               Registration Default           8
               Shelf Registration             3(a)
               Trustee                        Preamble

     Section 2.  Registered Exchange Offer.
                 -------------------------

          (a)  The Obligor shall:

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               (i)     prepare and, not later than 45 calendar days after the
          Escrow Merger Effective Date, file with the Commission an Exchange
          Offer Registration Statement on an appropriate form under the
          Securities Act with respect to a proposed offer to exchange (the
          "Registered Exchange Offer") any and all of the outstanding Notes
           -------------------------
          (including, if permitted by the then prevailing interpretations of the
          staff of the Commission, any Notes held by the Initial Purchasers
          having the status of an unsold allotment in the initial distribution)
          for a like aggregate principal amount of the Obligor's 13 3/4% Senior
          Notes due 2008 (the "Registered Notes");
                               ----------------

               (ii)    use its best efforts to cause the Exchange Offer
          Registration Statement to become effective under the Securities Act as
          soon as practicable thereafter, but in no event later than 150
          calendar days after the Escrow Merger Effective Date;

               (iii)   in connection with the foregoing, to file (A) all pre-
          effective amendments to such Exchange Offer Registration Statement as
          may be necessary in order to cause such Exchange Offer Registration
          Statement to become effective and (B) cause all necessary filings, if
          any, in connection with the registration and qualification of the
          Registered Notes to be made under the Blue Sky laws of such
          jurisdictions as are necessary to permit Consummation of the
          Registered Exchange Offer except that in no event shall the Obligor be
          obligated in connection therewith to qualify as a foreign corporation
          or to execute a general consent to service of  process or to take any
          other action that would subject it to service of process in suits in
          any jurisdiction other than those arising out of the offering or sale
          of the Notes in such jurisdiction pursuant to such Exchange Offer
          Registration Statement; and

               (iv)    upon the effectiveness of the Exchange Offer Registration
          Statement, unless it would not be permitted by applicable law or
          Commission policy, promptly commence the Registered Exchange Offer to
          enable each Holder of the Notes (other than Holders who are affiliates
          (within the meaning of the Securities Act) of the Obligor or
          underwriters (as defined in the Securities Act) with respect to the
          Registered Notes) to exchange the Notes for Registered Notes.

     The Obligor shall cause the Exchange Offer Registration Statement and the
     related Prospectus, as of the effective date of such Exchange Offer
     Registration Statement, (i) to comply with the applicable requirements of
     the Securities Act and (ii) not to contain any untrue statement of a
     material fact or omit to state a material fact required to be stated
     therein or necessary in order to make the statements therein, in light of
     the circumstances under which they were made, not misleading.

          (b)  The Obligor shall cause the Registered Exchange Offer to be
     Consummated in compliance with the Securities Act, the Exchange Act and all
     other applicable laws and regulations.  No securities other than the
     Registered Notes shall be included in the Exchange Offer Registration
     Statement.  The Obligor shall use its best

                                     - 4 -
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     efforts to cause the Registered Exchange Offer to be Consummated within 20
     Business Days, but in any event not later than 30 Business Days, after the
     effective date of the Exchange Offer Registration Statement. The Registered
     Exchange Offer shall be on an appropriate form under the Securities Act as
     to permit resales of Registered Notes by delivering the Prospectus
     contained in the Exchange Offer Registration Statement.

          (c) To the extent necessary to ensure that the Exchange Offer
     Registration Statement is available for sales of Registered Notes by
     Broker-Dealers, the Obligor shall use its best efforts to keep the Exchange
     Offer Registration Statement continuously effective and to amend and
     supplement the Prospectus contained therein in order to permit such
     Prospectus to be lawfully delivered by all persons subject to the
     prospectus delivery requirements of the Securities Act for a period of up
     to one year after the Consummation of the Registered Exchange Offer (or
     such longer period if extended pursuant to Section 4(c)(ix)).

          (d) In connection with the Registered Exchange Offer, the Obligor
     shall:

               (i)     mail, or cause to be mailed, to each Holder of the Notes
          a copy of the Prospectus forming a part of the Exchange Offer
          Registration Statement, together with an appropriate letter of
          transmittal and related documents;

               (ii)    keep the Registered Exchange Offer open for a period of
          not less than 20 Business Days after the date notice thereof is mailed
          to the Holders of the Notes (or longer if required by applicable law);

               (iii)   utilize the services of a depositary for the Registered
          Exchange Offer with an address in the Borough of Manhattan, The City
          of New York; and

               (iv)    permit Holders of the Notes to withdraw tendered Notes at
          any time prior to the close of business, New York time, on the last
          Business Day on which the Registered Exchange Offer shall remain open
          (the "Exchange Date").
                -------------

          (e) As soon as practicable after the Exchange Date, the Obligor shall:

               (i)     accept for exchange all Notes duly tendered and not
          validly withdrawn pursuant to the Registered Exchange Offer;

               (ii)    deliver or cause to be delivered to the Trustee for
          cancellation all Notes or portions thereof so accepted for exchange by
          the Obligor;

               (iii)   execute and deliver to, or cause to be delivered to, the
          Trustee for authentication and delivery, Registered Notes in an
          aggregate principal amount equal to the aggregate principal amount of
          the Notes so accepted for exchange; and

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               (iv)    cause the Trustee to authenticate and deliver promptly to
          each Holder of the Notes accepted for exchange, Registered Notes
          having an aggregate principal amount at maturity equal to the
          aggregate principal amount at maturity of the Notes surrendered by
          such Holder and accepted for exchange.

     Section 3.  Shelf Registration.
                 ------------------

          (a)  If:

               (i)     the Obligor is not required to file the Exchange Offer
          Registration Statement or permitted to Consummate the Registered
          Exchange Offer because the Registered Exchange Offer is not permitted
          by applicable law or Commission policy; or

               (ii)    any Holder of Transfer Restricted Securities notifies the
          Obligor prior to the 20th day following commencement of the Exchange
          Offer that (a) it is prohibited by law or Commission policy from
          participating in the Registered Exchange Offer, (b) that it may not
          resell the Registered Notes acquired by it in the Registered Exchange
          Offer to the public without delivering a prospectus and the prospectus
          contained in the Exchange Offer Registration Statement is not
          appropriate or available for such resales or (c) that it is a Broker-
          Dealer and owns Notes acquired directly from the Obligor or an
          affiliate of the Obligor,

     then the Obligor shall take the following actions:

               (A)     After the occurrence of one of the events described in
          3(a)(i) or (ii), the Obligor shall prepare and file with the
          Commission as promptly as practicable but in no event later than 30
          days after the occurrence of one of the events described in 3(a)(i) or
          (ii) and in any event within 60 days after the Escrow Merger Effective
          Date, a Shelf Registration Statement on an appropriate form under the
          Securities Act relating to the offer and sale by the Holders of the
          Notes in accordance with the methods of distribution set forth in the
          Shelf Registration Statement and Rule 415 under the Securities Act (a
          "Shelf Registration") and use its best efforts to cause such Shelf
           ------------------
          Registration Statement to be declared effective as promptly as
          practicable after such filing but in no event later than 90 calendar
          days after the occurrence of one of the events described in 3(a)(i) or
          (ii); and

               (B)     The Obligor shall use its best efforts to keep the Shelf
          Registration Statement continuously effective, and agrees to amend or
          supplement the prospectus contained therein (and use its best efforts
          to cause any such amendment to become and remain effective) in order
          to permit the prospectus included therein to be available for resales
          of, and lawfully delivered by the Holders of, the Notes covered
          thereby, until the earlier of (x) the second anniversary of the Escrow
          Merger Effective Date (or for such

                                     - 6 -
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          longer period if extended pursuant to Section 4(i)(ix)), (y) such time
          as all the Notes covered by such Shelf Registration Statement have
          been sold pursuant thereto or (z) the date on which all persons that
          are not affiliates may resell the Notes pursuant to Rule 144(k) under
          the Securities Act or the date on which the Notes otherwise cease to
          be Transfer Restricted Securities.

          (b)  The Obligor shall cause any Shelf Registration Statement
     and the related prospectus and any amendment or supplement thereto, as of
     the effective date of such Shelf Registration Statement, amendment or
     supplement, (i) to comply in all materials respects with the applicable
     requirements of the Securities Act and (ii) not to contain any untrue
     statement of a material fact or omit to state a material fact required to
     be stated therein or necessary in order to make the statements therein, in
     the light of the circumstances under which they were made, not misleading.

     Section 4.  Registration Procedures.
                 -----------------------

          (a)  Registered Exchange Offer.  In connection with the Registered
               -------------------------
     Exchange Offer:

               (i)     the Obligor shall comply with all of the provisions of
          Section 4(c) below (other than those that are not applicable);

               (ii)    prior to effectiveness of the Exchange Offer Registration
          Statement, if the Commission so requests, the Obligor shall make the
          following representations (in substantially the form set forth below)
          to the staff of the Commission:

                       (A) that the Obligor is registering the Registered Notes
               and the Registered Exchange Offer in reliance on the position of
               the staff of the Commission enunciated in the Exxon Capital
                                                             -------------
               Holdings Corporation Commission no-action letter (available May
               --------------------
               13, 1988) and the Morgan Stanley and Co., Inc. Commission no-
                                 ----------------------------
               action letter (available June 5, 1991), as interpreted in the
               Shearman & Sterling Commission no-action letter (available July
               -------------------
               2, 1993); and

                       (B) that the Obligor has not entered into any arrangement
               or understanding with any person to distribute the Registered
               Notes to be received in the Registered Exchange Offer and that,
               to the best of the Obligor's information and belief, each Person
               participating in the Registered Exchange Offer is acquiring the
               Registered Notes in its ordinary course of business and has no
               arrangement or understanding with any person to participate in
               the distribution of the Registered Notes to be received in the
               Registered Exchange Offer. In this regard, the Obligor will make
               each person participating in the Registered Exchange Offer aware
               (through the Prospectus included in the Exchange Offer
               Registration Statement or otherwise) that, if the Registered
               Notes and the Registered Exchange Offer are being registered for
               the purpose of
                                     - 7 -
<PAGE>

               secondary resales of the Registered Notes, any Holder using the
               Registered Exchange Offer to participate in a distribution of the
               Registered Notes (1) could not rely on the staff position
               enunciated in such Exxon Capital Holdings Corporation letter or
               similar letters and (2) must comply with registration and
               prospectus delivery requirements of the Securities Act in
               connection with any secondary resale transaction of the
               Registered Notes. The Obligor acknowledges that such a secondary
               resale transaction should be covered by an effective registration
               statement containing the selling security holder information
               required by Item 507 of Regulation S-K;

               (iii)   the Obligor will require each Holder that is a Broker-
          Dealer and that is the beneficial owner (as defined in Rule 13d-3
          under the Exchange Act) of Notes acquired for its own account as a
          result of market-making activities or other trading activities (a
          "Participating Broker-Dealer"), to include a representation in such
           ---------------------------
          Participating Broker-Dealer's letter of transmittal with respect to
          the Registered Exchange Offer that such Participating Broker-Dealer
          has not entered into any arrangement or understanding with the Obligor
          or any affiliate of the Obligor to distribute the Registered Notes;

               (iv)    the Obligor (1) will make each Person participating in
          the Registered Exchange Offer aware (through the Prospectus included
          in the Exchange Offer Registration Statement or otherwise) that any
          Broker-Dealer who holds Notes acquired for its own account as a result
          of market-making activities or other trading activities, and who
          receives Registered Notes in exchange for such Notes pursuant to the
          Registered Exchange Offer, may be a statutory underwriter and in
          connection with any resale of such Registered Notes must deliver a
          Prospectus meeting the requirements of the Securities Act and
          describing the methods by which Participating Broker-Dealers may
          resell such Registered Notes, and (2) will include in the transmittal
          letter or similar documentation to be executed by an exchange offeree
          in order to participate in the Registered Exchange Offer the following
          additional provision:

               "If the undersigned is a broker-dealer holding Notes acquired for
               its own account as a result of market-making activities or other
               trading activities, the undersigned hereby acknowledges that it
               will deliver a prospectus meeting the requirements of the
               Securities Act in connection with any resale of Registered Notes
               received in respect of such Notes pursuant to the Registered
               Exchange Offer"

          and the transmittal letter or similar documentation may also include a
          statement to the effect that by so acknowledging and by delivering a
          Prospectus, a Broker-Dealer will not be deemed to admit that it is an
          "underwriter" within the meaning of the Securities Act;

                                     - 8 -
<PAGE>

               (v)     as a condition to its participation in the Registered
          Exchange Offer pursuant to the terms of this Agreement, each Holder of
          the Notes who tenders such Notes pursuant to the Registered Exchange
          Offer shall furnish a written representation to the Obligor (which may
          be contained in the letter of transmittal contemplated by the Exchange
          Offer Registration Statement) to the effect that by accepting the
          Registered Exchange Offer, such Holder represents to the Obligor that:

                    (A) it is not an affiliate of the Obligor (within the
               meaning of the Securities Act);

                    (B) it is not engaged in and does not intend to engage in,
               and has no arrangement or understanding with any person to
               participate in, a distribution of the Registered Notes to be
               issued in the Registered Exchange Offer;

                    (C) it is acquiring the Registered Notes in its ordinary
               course of business; and

                    (D) if it is a Participating Broker-Dealer holding Notes
               acquired for its own account as a result of market-making
               activities or other trading activities, it acknowledges that it
               will deliver a Prospectus meeting the requirements of the
               Securities Act in connection with any resale of Registered Notes
               received in respect of such Notes pursuant to the Registered
               Exchange Offer;

          and the transmittal letter or similar documentation may also include a
          statement to the effect that by so acknowledging and by delivering a
          Prospectus, a Broker-Dealer will not be deemed to admit that it is an
          "underwriter" within the meaning of the Securities Act; and

               (vi)    the Obligor shall include within the Prospectus contained
          in the Exchange Offer Registration Statement a section entitled "Plan
          of Distribution," which shall contain:

                    (A) a statement substantially to the effect that any Broker-
               Dealer and any Holder using the Registered Exchange Offer to
               participate in a distribution of the Registered Notes to be
               acquired in the Registered Exchange Offer:

                         (I) could not under Commission policy as in effect on
                    the date of this Agreement rely on the position of the
                    Commission enunciated in the Morgan Stanley and Co., Inc.
                                                 ----------------------------
                    Commission no-action letter (available June 5, 1991) and the
                    Exxon Capital Holdings Corporation Commission no-action
                    ----------------------------------
                    letter (available May 13, 1988), as interpreted in the to

                    Shearman &
                    -----------

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                    Sterling Commission no-action letter (available
                    --------
                    July 2, 1993), and similar no-action letters, and

                         (II)  must comply with the registration and prospectus
                    delivery requirements of the Securities Act in connection
                    with a secondary resale transaction of the Registered Notes
                    and that such a secondary resale transaction should be
                    covered by an effective registration statement containing
                    the selling security holder information required by Item 507
                    or 508, as applicable, of Regulation S-K under the
                    Securities Act; and

                    (B) a summary statement of the positions taken or policies
               made by the staff of the Commission with respect to the potential
               "underwriter" status of any Participating Broker-Dealer.

     Such "Plan of Distribution" section shall also allow the use of the
Prospectus by Participating Broker-Dealers for a period of one year from the
Consummation of the Exchange Offer, or such shorter period as will terminate
when all the Notes acquired by Participating Broker-Dealers have been exchanged
for the Registered Notes and resold by such Broker-Dealers, and include a
statement to the effect that any Broker-Dealer who holds Notes acquired for its
own account as a result of market-making activities or other trading activities,
and who receives Registered Notes in exchange for such Notes pursuant to the
Registered Exchange Offer, may be a statutory underwriter and must deliver a
Prospectus meeting the requirements of the Securities Act in connection with any
resale of such Registered Notes and that any profit or commissions received by
such Broker-Dealer may be deemed to be underwriting compensation under the
Securities Act, and describing the means by which Participating Broker-Dealers
may resell the Registered Notes.  The "Plan of Distribution" section in the
Prospectus contained in the Exchange Offer Registration Statement shall not name
any such Participating Broker-Dealer or disclose the amount of Notes held by any
such Participating Broker-Dealer except to the extent required by Commission
policy.

          (b) Shelf Registration Statement.  In connection with any Shelf
              ----------------------------
     Registration Statement, the Obligor shall comply with all the provisions of
     Section 4(c) below  (other than those that are not applicable) and shall
     effect such registration to permit the resale of Notes being sold in
     accordance with the intended method or methods of distribution set forth in
     the Shelf Registration Statement.

          (c) Registration Procedures.  In connection with any Registration
              -----------------------
     Statement and any Prospectus required by this Agreement, the Obligor shall:

               (i)     prepare and file with the Commission a Registration
          Statement on the appropriate form under the Securities Act, which
          form: (x) shall be selected by the Obligor; (y) shall, in the case of
          a Shelf Registration Statement, be available for the sale of Notes by
          the selling Holders thereof; and (z) shall comply as to form with the
          requirements of the Securities Act, and include all financial
          statements required by the Commission to be filed therewith, and use

                                    - 10 -
<PAGE>

          its best efforts to cause such Registration Statement to become
          effective and to keep such Registration Statement continuously
          effective for the period provided for in Section 2, in the case of an
          Exchange Offer Registration Statement, and for the period provided for
          in Section 3, in the case of a Shelf Registration Statement;

               (ii)  (A) prepare and file with the Commission such amendments
          and post-effective amendments to such Registration Statement as may be
          necessary to keep such Registration Statement effective for the
          applicable period set forth in Section 2 or Section 3, as the case may
          be; and (B) cause each Prospectus to be supplemented by any required
          prospectus supplement, and, as so supplemented, cause the Prospectus
          to be filed pursuant to Rule 424 under the Securities Act and to
          comply in all material respects with the applicable provisions of
          Rules 424 and 430A under the Securities Act in a timely manner;

               (iii) advise the Initial Purchasers, each Holder of the Notes
          included in the Shelf Registration Statement and, with respect to the
          Exchange Offer Registration Statement, any Participating Broker-Dealer
          from whom the Obligor has received prior written notice that it will
          be a Participating Broker-Dealer in the Registered Exchange Offer:

                    (A) when each Registration Statement or any amendment
               thereto has been filed with the Commission and when each such
               Registration Statement or any post-effective amendment thereto
               has been declared effective;

                    (B) of any request by the Commission for amendments or
               supplements to a Registration Statement or the Prospectus
               included therein or for additional information;

                    (C) of the issuance by the Commission of any stop order
               suspending the effectiveness of a Registration Statement or the
               initiation or threatening of any proceedings for that purpose;

                    (D) of the receipt by either of the Obligor or its legal
               counsel of any notification with respect to the suspension of the
               qualification of the Notes or the Registered Notes for sale in
               any jurisdiction or the initiation or threatening of any
               proceeding for such purpose;

                    (E) when the prospectus contained in any Registration
               Statement may not be used for offers or sales of the Registered
               Notes because (x) of the existence of any fact or the happening
               of any event (including any material non-public information) that
               makes untrue any statement of a material fact made in the
               Registration Statement, the Prospectus, any amendment or
               supplement thereto or any document incorporated by reference
               therein, or that requires the making of any additions to or
               changes in the Registration Statement or the Prospectus

                                    - 11 -
<PAGE>

               in order to make the statements therein not misleading or (y)
               such prospectus shall not contain the current information
               required by the Securities Act; it being understood that any
               notice delivered pursuant to this subparagraph need not
               specifically recite the reasons for its delivery, provided that
               the Obligor consults with the Initial Purchasers prior to
               delivery of such notice as to the reasons underlying such notice
               need;

               (iv)    use its best efforts to prevent the issuance of any order
          of the Commission suspending the effectiveness of a Registration
          Statement; and if at any time the Commission shall issue any stop
          order suspending the effectiveness of the Registration Statement, or
          any state securities commission or other regulatory authority shall
          issue an order suspending the qualification or exemption from
          qualification of the Notes or the Registered Notes under state
          securities or Blue Sky laws, the Obligor shall use its best efforts to
          obtain the withdrawal of such order at the earliest possible time, and
          provide prompt notice of the withdrawal of any such order to each
          Holder of any Notes included in the Shelf Registration Statement, and,
          with respect to the Exchange Offer Registration Statement, to any
          Participating Broker-Dealer participating in the Registered Exchange
          Offer;

               (v)     furnish to each of the Initial Purchasers, upon request,
          and, in the case of a Shelf Registration, to each Holder of any Notes
          included in the Shelf Registration Statement, and counsel to the
          Initial Purchasers referred to in Section 6, a reasonable time prior
          to filing with the Commission, copies of any Registration Statement or
          any Prospectus included therein and any amendments or supplements
          thereto (including all documents incorporated by reference prior to
          the effectiveness of such Registration Statement), which documents,
          other than documents incorporated by reference, will be subject to the
          review of the Initial Purchasers for a period of at least five
          Business Days, and the Obligor may, in its reasonable discretion,
          reflect in each such document when so filed with the Commission, such
          comments as the Initial Purchasers or such Holders reasonably may
          propose within five Business Days after the receipt thereof;

               (vi)    promptly prior to the filing of any document that is to
          be incorporated by reference into a Registration Statement or
          Prospectus subsequent to the effectiveness thereof (A) if requested,
          provide copies of such document to any Holder of any Notes included in
          such Registration Statement, to the Initial Purchasers and (B) make
          representatives of the Obligor available for discussion of such
          document and other customary due diligence matters, and (C) the
          Obligor may, in its reasonable discretion, include such information in
          such document prior to the filing thereof as Holders or the Initial
          Purchasers may reasonably request;

                                    - 12 -
<PAGE>

               (vii) (A)  make available at reasonable times for inspection by
          the Initial Purchasers and, in the case of a Shelf Registration,
          Holders of any Notes included in such Registration Statement, and any
          attorney or accountant retained by such Holder or the Initial
          Purchasers, or any underwriter participating in any disposition
          pursuant to a Shelf Registration Statement, all relevant financial and
          other records, pertinent corporate documents and properties of the
          Obligor and (B) cause the officers, directors and employees of the
          Obligor to supply all information reasonably requested by any such
          Holder, Initial Purchaser, attorney, accountant or underwriter in
          connection with such Registration Statement subsequent to the filing
          thereof and prior to its effectiveness, in each case, as is customary
          for similar due diligence examinations;

               (viii)  if requested by any selling Holders in connection with a
          Shelf Registration Statement or the Initial Purchasers in connection
          with market making activities, (A) promptly incorporate in any
          Registration Statement or Prospectus, pursuant to a supplement or
          post-effective amendment if necessary, such information as such
          Holders or the Initial Purchasers may reasonably request, and to which
          the Obligor does not reasonably object, to have included therein,
          including, without limitation, information relating to the "Plan of
          Distribution" of the Notes, the purchase price being paid therefor and
          any other terms of the offering of the Notes to be sold in such
          offering, and (B) make all required filings of any such Prospectus
          supplement or post-effective amendment as promptly as practicable
          after the Obligor is notified of the matters to be incorporated in
          such Prospectus supplement or post-effective amendment;

               (ix)  upon the occurrence of any event of the kind described in
          Section 4(c)(iii)(E) or any other event that would cause such
          Registration Statement or the Prospectus contained therein not to be
          effective and usable for resales of Notes or Registered Notes during
          the period required by this Agreement, promptly (except as
          contemplated by Section 2(c) or 3(a)(ii)(B) hereof) prepare a post-
          effective amendment to the applicable Registration Statement or a
          supplement to the related Prospectus and use its best efforts to cause
          such amendment to be declared effective, or file any other required
          document so that the Registration Statement and the Prospectus, as
          thereafter delivered to Holders of the Transfer Restricted Securities
          or the purchasers of Transfer Restricted Securities, (A) will not
          contain an untrue statement of a material fact or omit to state any
          material fact necessary to make the statements therein, in light of
          the circumstances under which they were made, not misleading and (B)
          will contain all information required by the Securities Act.  If any
          of the Initial Purchasers, the Holders of any Notes or Registered
          Notes covered by a Registration Statement or any known Participating
          Broker-Dealer is required by the terms of this Agreement to suspend
          the use of a Prospectus until the requisite changes to such Prospectus
          have been made, then the period of effectiveness of the applicable
          Shelf Registration Statement provided for in Section 3 and the
          Exchange Offer Registration Statement provided for in

                                    - 13 -
<PAGE>

          Section 2 shall each be extended by the number of days during the
          period from and including the date such notice is required to be given
          under this Agreement to and including the date when the Initial
          Purchasers, each selling Holder covered by such Registration
          Statement, and any known Participating Broker-Dealer shall have
          received an amended or supplemented Prospectus contemplated by this
          clause (ix) or shall have received Advice (as defined below) from the
          Obligor;

               (x)     in the case of a Registered Exchange Offer, deliver to
          each of the Initial Purchasers one manually signed copy of the
          Exchange Offer Registration Statement without charge and with any
          post-effective amendment thereto, including financial statements and
          schedules, and, if the Initial Purchasers request, all exhibits
          (including those, if any, incorporated by reference);

               (xi)    in the case of a Registered Exchange Offer, deliver to
          each of the Initial Purchasers, any Participating Broker-Dealer and
          such other persons required to deliver a Prospectus in connection with
          the offering and sale of the Registered Notes following the Registered
          Exchange Offer, without charge, as many copies of the final Prospectus
          included in the Exchange Offer Registration Statement and any
          amendment or supplement thereto as such persons may reasonably
          request, and, in connection therewith, the Obligor hereby consents,
          subject to any notice by the Obligor in accordance with this Section
          4(c) of the existence of any fact or event of the kind described in
          Section 4(c)(iii)(E), to the use of the Prospectus or any amendment or
          supplement thereto by the Initial Purchasers, if necessary, any
          Participating Broker-Dealer and such other persons as are required to
          deliver a Prospectus following the Registered Exchange Offer in
          connection with the offering and sale of the Registered Notes covered
          by the Prospectus, or any amendment or supplement thereto, included in
          such Exchange Offer Registration Statement;

               (xii)   in the case of a Shelf Registration, furnish to each of
          the Initial Purchasers, without charge, one manually signed copy of
          the Shelf Registration Statement and any post-effective amendment
          thereto, including financial statements and schedules, and, if the
          recipient Holder so requests, all exhibits (including those, if any,
          incorporated by reference);

               (xiii)  in the case of a Shelf Registration, deliver, without
          charge, to each of the Initial Purchasers and each Holder of the Notes
          included within the coverage of a Shelf Registration Statement which
          was declared effective by the Commission as many copies of the
          Prospectus (including each preliminary prospectus) included in such
          Shelf Registration Statement and any amendment or supplement thereto
          as such person may reasonably request, and, in connection therewith,
          the Obligor hereby consents, subject to any notice by the Obligor in
          accordance with this Section 4(c) of the existence of any fact or
          event of the kind described in Section 4(c)(iii)(E), to the use of the
          Prospectus or any amendment or supplement thereto by each of the
          selling Holders of the

                                    - 14 -
<PAGE>

          Notes in connection with the offering and sale of the Notes covered by
          the Prospectus, or any amendment or supplement thereto, included in
          such Shelf Registration Statement;

               (xiv)   in the case of a Shelf Registration, (A) enter into such
          customary agreements and take all such other actions in connection
          therewith in order to expedite or facilitate the offering or
          disposition of the Notes included in the Shelf Registration Statement,
          including, but not limited to, furnishing to the Initial Purchasers
          and each Holder of any Notes included in the Shelf Registration
          Statement, in such substance and scope as they may request and as are
          customarily made by issuers to underwriters in primary underwritten
          offerings, upon the date of the effectiveness of the Shelf
          Registration Statement:

                         (1) a certificate, dated the date of effectiveness of
                    the Shelf Registration Statement, signed by (x) the
                    president or chief executive officer of the Obligor and (y)
                    the chief financial officer or the principal financial or
                    accounting officer of the Obligor, confirming, as of the
                    date thereof, that the Shelf Registration Statement and the
                    related Prospectus do not contain any untrue statement of a
                    material fact or omit to state a material fact required to
                    be stated therein or necessary to make the statements
                    therein not misleading and as to such other matters as such
                    parties may reasonably request;

                         (2) opinions, dated the date of effectiveness of the
                    Shelf Registration Statement, of outside counsel for the
                    Obligor, covering such matters as are customarily included
                    in opinions to underwriters in primary underwritten
                    offerings and as are reasonably requested by such parties;
                    and

                         (3) a customary comfort letter, dated as of the date of
                    effectiveness of the Shelf Registration Statement, from the
                    independent certified public accountants of the Obligor, in
                    customary form and covering matters of the type customarily
                    covered in comfort letters by underwriters in connection
                    with primary underwritten offerings, and addressing, to the
                    extent relevant, the matters set forth in the Initial
                    Letters (as defined in the Purchase Agreement) delivered
                    pursuant to the Purchase Agreement;

                    (B) in the case of an underwriting agreement entered into in
               connection with a Shelf Registration, set forth in full
               indemnification provisions and procedures substantially in the
               form of those set forth in Section 7 hereof with respect to all
               parties required to be indemnified pursuant to such Section 7;
               and

                                     - 15 -
<PAGE>

                    (C) deliver such other documents and certificates as may be
               reasonably requested by such parties to evidence compliance with
               clause (A) above.

               (xv)    prior to any public offering of any Notes pursuant to a
          Shelf Registration Statement, (A) cooperate with the selling Holders
          participating in a Shelf Registration, and their respective counsel,
          in connection with the registration and qualification of the Notes
          under the securities or Blue Sky laws of such jurisdictions as the
          selling Holders may request, and (B) do any and all other acts or
          things necessary or advisable to enable the offering or disposition in
          such jurisdictions of the Notes, as the case may be, covered by the
          Shelf Registration Statement; except that in no event shall the
          Obligor be obligated in connection therewith to qualify as a foreign
          corporation or to execute a general consent to service of process or
          to take any other action that would subject it to service of process
          in suits in any jurisdiction other than those arising out of the
          offering or sale of Notes in such jurisdiction pursuant to such
          Registration Statement;

               (xvi)   to the extent that any Notes are held in certificated
          form and are not represented by global certificates, cooperate with
          the holders of such Notes, in connection with the Registered Exchange
          Offer, to include an aggregate principal amount of such Notes in a
          global certificate representing the Registered Notes, and, to the
          extent that any Notes or Registered Notes are not eligible to be held
          in book-entry form, prepare and deliver Notes or Registered Notes in
          certificated form as the Holders may request; provided, in either
          case, that the Obligor will cooperate with participating Broker
          Dealers (in the case of a Registered Exchange Offer) and any Holders
          selling Notes pursuant to a Shelf Registration Statement, to
          facilitate the timely delivery of such certificates (whether in book-
          entry or certificated form as provided above) representing such
          Registered Notes or Notes, as the case may be, to be sold which do not
          bear any restrictive legends (other than any customary legend required
          by the applicable depository or any legend that would be required by a
          Note or Registered Note held by an affiliate of the Obligor);

               (xvii)  use its best efforts to cause the Notes or Registered
          Notes covered by the Registration Statement to be registered with or
          approved by such other governmental agencies or authorities (except as
          may be required solely as consequence of a Holder's business) as may
          be necessary to enable the Consummation of the Registered Exchange
          Offer or, in the case of a Shelf Registration, as may be applicable to
          the Obligor with respect to filing and having declared effective the
          Shelf Registration Statement;

               (xviii) obtain appropriate CUSIP numbers for each series of
          Registered Notes not later than the effective date of the Registration
          Statement and provide the Trustee with printed certificates for the
          Notes or Registered Notes, as the case may be, in a form eligible for
          deposit with The Depository Trust

                                    - 16 -
<PAGE>

          Company, or with Morgan Guaranty Trust Company of New York, Brussels
          Office, as operator of the Euroclear System and Cedel Bank, Societe
          Anonyme;

               (xix)   otherwise use its best efforts to comply with all
          applicable rules and regulations of the Commission, and make generally
          available to its security holders, as soon as practicable, an earnings
          statement meeting the requirements of Rule 158 (which need not be
          audited) covering a period of at least 12 months beginning after the
          effective date of a Registration Statement; and

               (xx)    cause the Indenture to be qualified under the TIA not
          later than the effective date of the first Registration Statement
          required to be filed by this Agreement, and, in connection therewith:
          (A) cooperate with the Trustee and the Holders of Notes to effect such
          changes to the Indenture as may be required for such Indenture to be
          so qualified in accordance with the terms of the TIA; and (B) execute,
          and use all reasonable efforts to cause the Trustee to execute, all
          documents that may be required to effect such changes and all other
          forms and documents required to be filed with the Commission to enable
          such Indenture to be so qualified in a timely manner.

          The Initial Purchasers, each Holder of Notes included in a Shelf
Registration Statement and each Participating Broker-Dealer using the Prospectus
included in the Exchange Offer Registration Statement for the resale of
Registered Notes, by its acquisition of a Note or a Registered Note, agrees
that, upon receipt of any notice from the Obligor of the existence of any fact
or event of the kind described in Section 4(c)(iii)(E), the Initial Purchasers,
Holder or Participating Broker-Dealer will forthwith discontinue disposition of
the Notes or the Registered Notes, as applicable, and suspend the use of the
Prospectus until the Initial Purchasers, Holder or Participating Broker-Dealer
have received copies of a supplemented or amended Prospectus as contemplated by
Section 4(c)(ix), or until it is advised in writing by the Obligor that the use
of the Prospectus may be resumed, and has received copies of any additional or
supplemental filings that are incorporated by reference in the Prospectus.  If
so directed by the Obligor, the Initial Purchasers, each such selling Holder of
Notes or each such Participating Broker-Dealer, as the case may be, will deliver
to the Obligor (at the expense of the Obligor) all copies, other than permanent
file copies then in such Holder's, Initial Purchaser's or Participating Broker-
Dealer's possession, of the Prospectus covering such Notes or Registered Notes,
as applicable, that was current at the time of receipt of such notice.

     Section 5.  Hold-Back Agreements.
                 --------------------

          The Obligor agrees that neither it nor any affiliate, without the
prior written consent of Bear, Stearns & Co. Inc., will effect any public or
private sale or distribution (in  cluding a sale pursuant to Regulation D under
the Securities Act) of any securities the same as or similar to those covered by
a Registration Statement filed pursuant to Section 2 or 3 hereof, or any
securities convertible into or exchangeable or exercisable for such securities,
from the date of this Agreement until 180 calendar days after the Escrow Merger
Effective Date.

                                    - 17 -
<PAGE>

     Section 6.  Registration Expenses.
                 ---------------------

          All expenses incident to the Obligor's performance of or compliance
with its obligations under Sections 2, 3 and 4 of this Agreement will be borne
by the Obligor regardless of whether a Registration Statement becomes effective,
and, in the case of a Shelf Registration Statement, the Obligor will reimburse
the Holders covered thereby for the reasonable fees and disbursements of one
counsel, who shall be Skadden, Arps, Slate, Meagher & Flom LLP, unless another
firm shall be designated by the Holders of a majority of the principal amount of
the Notes or such Registered Notes included in any such Registration Statement.

     Section 7.  Indemnification and Contribution.
                 --------------------------------

          (a) In connection with any Registration Statement, the Obligor agrees
     to indemnify and hold harmless (i) each of the Initial Purchasers, each
     Participating Broker-Dealer and each Holder of Notes to be included in such
     Registration Statement, (ii each person, if any, who controls (within the
     meaning of Section 15 of the Securities Act or Section 20 of the Exchange
     Act) such Initial Purchaser, Participating Broker-Dealer or Holder (any of
     the persons referred to in this clause (ii) being hereinafter referred to
     as a "controlling person") and (ii the respective officers, directors,
           ------------------
     partners, employees, representatives and agents of any such Initial
     Purchaser, Participating Broker-Dealer or Holder or controlling person (any
     person referred to in clause (i), (ii) or (iii) may hereinafter be referred
     to as an "Indemnified Holder") from and against any and all losses,
               ------------------
     liabilities, claims, damages and expenses whatsoever as incurred
     (including, but not limited to, reasonable attorneys' fees and any and all
     reasonable expenses whatsoever incurred in investigating, preparing or
     defending against any litigation, commenced or threatened, or any claim
     whatsoever, and, subject to Section 7(c), any and all amounts paid in
     settlement of any claim or litigation), jointly or severally, to which any
     such Indemnified Holder may become subject under the Securities Act, the
     Exchange Act or otherwise (collectively, "Losses"), insofar as such Losses
                                               ------
     (or actions or proceedings in respect thereof) arise out of or are based
     upon any untrue statement or alleged untrue statement of a material fact
     contained in any Registration Statement or Prospectus, or any amendment or
     supplement thereto, or any omission or alleged omission to state therein a
     material fact required to be stated therein or necessary to make the
     statements therein, in the light of the circumstances under which they were
     made, not misleading; provided, however, that the Obligor will not be
     liable in any such case to the extent, but only to the extent, that any
     such Loss (or action or proceeding in respect thereof) arises out of or is
     based upon an untrue statement or alleged untrue statement in or omission
     or alleged omission from the Registration Statement or Prospectus contained
     therein made in reliance upon and in conformity with written information
     furnished to the Obligor by or on behalf of such Indemnified Holder
     expressly for use therein. This indemnity obligation will be in addition to
     any liability which the Obligor may otherwise have to such Indemnified
     Holder, including under this Agreement.

          (b) The Obligor hereby also agrees that in connection with any
     underwritten offering of Transfer Restricted Securities pursuant to Section
     3, the Obligor will also

                                    - 18 -
<PAGE>

     indemnify any underwriters, selling brokers, dealers and similar securities
     industry professionals participating in the distribution, their officers,
     directors, employees, agents, advisors and representatives, and each
     controlling person thereof, substantially to the same extent as provided in
     Section 7(a) with respect to the indemnification of the Initial Purchasers
     and Holder of Transfer Restricted Securities (and such Persons will
     indemnify the Obligor and each controlling person thereof to the same
     extent as provided in Section 7(c)).

          (c) Each Initial Purchaser will, severally and not jointly, indemnify
     and hold harmless the Obligor, each of the directors of the Obligor, each
     of the officers of the Obligor and each other person, if any, who controls
     the Obligor (within the meaning of Section 15 of the Securities Act or
     Section 20 of the Exchange Act) against any Losses to which they or any of
     them may become subject under the Securities Act, the Exchange Act or
     otherwise, from and against any Losses insofar as such Losses (or actions
     or proceedings in respect thereof) arise out of or are based upon any
     untrue statement or alleged untrue statement of a material fact contained
     in any Registration Statement or Prospectus contained therein or any
     amendment or supplement thereto or the omission or alleged omission to
     state therein a material fact required to be stated therein or necessary to
     make the statements therein, in light of the circumstances under which they
     were made, not misleading, but in each case only to the extent that the
     untrue statement or alleged untrue statement or omission or alleged
     omission was made in reliance upon and in conformity with written
     information furnished to the Obligor by or on behalf of such Initial
     Purchaser specifically for use therein, and shall reimburse the Obligor for
     any legal or other expenses reasonably incurred by the Obligor in
     connection with investigating or preparing to defend or defending against
     or appearing as third party witness in connection with any such Loss as
     such expenses are incurred.

          (d) Promptly after receipt by an indemnified party under subsection
     (a) or (c) of this Section 7 of notice of the commencement of any claim or
     action, such indemnified party shall, if a claim in respect thereof is to
     be made against the indemnifying party under such subsection, notify each
     party against whom indemnification is to be sought in writing of the
     commencement thereof (but the failure so to notify an indemnifying party
     shall not relieve it from any liability which it may have under this
     Section 7 or otherwise).  In case any claim or such action is brought
     against any indemnified party, and such indemnified party notifies an
     indemnifying party of the commencement thereof, the indemnifying party will
     be entitled to participate in the defense thereof, and to the extent such
     indemnifying party may elect by written notice delivered to the indemnified
     party promptly after receiving the aforesaid notice from such indemnified
     party to assume the defense thereof with counsel reasonably satisfactory to
     such indemnified party. Notwithstanding the foregoing, the indemnified
     party or parties shall have the right to employ its or their own counsel in
     any such case, but the fees and expenses of such counsel shall be at the
     expense of such indemnified party or parties unless (a) the employment of
     such counsel shall have been authorized in writing by one of the
     indemnifying parties in connection with the defense thereof, (b) the
     indemnifying parties shall not have employed counsel to have charge of the
     defense thereof within a reasonable time after

                                    - 19 -
<PAGE>

     notice of commencement of the action, or (c) such indemnified party or
     parties shall have reasonably concluded that there may be defenses
     available to it or them which are different from or additional to those
     available to one or all of the indemnifying parties (in which case the
     indemnifying parties shall not have the right to direct the defense of such
     action on behalf of the indemnified party or parties), in any of which
     events such fees and expenses shall be borne by the indemnifying parties
     (it being understood, however, that the indemnifying party shall not be
     liable in any one claim or action or separate but substantially similar or
     related claims or actions in the same jurisdiction for the expenses of more
     than one separate counsel and one additional local counsel). Anything in
     this subsection to the contrary notwithstanding, an indemnifying party
     shall not be liable for any settlement of any claim or action effected
     without its written consent (which consent may not be unreasonably
     withheld). No indemnifying party shall, without the prior written consent
     of the indemnified party, effect any settlement of any pending or
     threatened proceeding in respect of which any indemnified party is or could
     have been a party and indemnity could have been sought hereunder by such
     indemnified party, unless such settlement includes an unconditional release
     of such indemnified party from all liability or claims that are the subject
     matter of such proceeding.

          (e) If the foregoing indemnification is unavailable or insufficient to
     an indemnified party for any reason in respect to any Losses or
     reimbursable expenses referred to therein, then in lieu of indemnification,
     each indemnifying party shall contribute to the amount paid or payable,
     including expenses, by such indemnified party in such proportion as is
     appropriate to reflect the relative benefits received (or anticipated to be
     received) by the indemnifying party or parties on the one hand and the
     indemnified party on the other from the offering of the Notes or Registered
     Notes, as the case may be, or, if such allocation is not permitted by
     applicable law, then in such proportion as is appropriate to reflect not
     only the relative benefits received (or anticipated to be received) but
     also the relative fault of each of the parties in connection with the
     statements or omissions or alleged statements or omissions that resulted in
     such Losses, as well as any other relevant equitable considerations.  The
     relative fault of the parties shall be determined by reference to, among
     other things:  (i) whether any losses, claims, damages or liabilities
     relate to information supplied by the Obligor or such Holder of Notes or
     such other indemnified person, as the case may be; (ii) the parties'
     relative intent, knowledge, access to information and opportunity to
     correct or prevent such statement or omission; and (iii) any other
     equitable considerations appropriate in the circumstances.  The Obligor and
     each indemnified party agrees that it would not be just and equitable if
     the amount of such contribution were determined by pro rata allocation or
     by any other method of allocation that does not take into account the
     equitable considerations referred to in the first sentence of this
     paragraph (e).  Notwithstanding any other provision of this paragraph (e),
     the Holders of the Notes or Registered Notes shall not be obligated to make
     contributions hereunder in any amount in excess of the amount by which the
     net proceeds received by such Holders from the sale of the Notes exceeds
     the amount of damages which such Holders have otherwise been required to
     pay in respect of the same or any substantially similar claim, and no
     person guilty of fraudulent misrepresentation (within the meaning of
     Section 11(f) of the Securities Act) shall be entitled to

                                    - 20 -
<PAGE>

     contribution from any person who was not guilty of such fraudulent
     misrepresentation. The obligations of the Holders to contribute pursuant to
     this Section 7(e) are several in proportion to the respective principal
     amount of Notes or Registered Notes held by each of the Holders hereunder
     and not joint. For purposes of this Section 7(e), each director, officer,
     employee and agent of any indemnified party and each person, if any, who
     controls such indemnified party (within the meaning of Section 15 of the
     Securities Act or Section 20 of the Exchange Act) shall have the same
     rights to contribution as such indemnified party and each director and
     officer of the Obligor, and each person, if any, who controls the Obligor
     (within the meaning of Section 15 of the Securities Act or Section 20 of
     the Exchange Act) shall have the same rights to contribution as the
     Obligor.

          (f) The foregoing provisions are in addition to any rights that an
     indemnified party may have at common law or otherwise.  The agreements
     contained in this Section 7 shall survive the sale of the Notes or the
     Registered Notes pursuant to a Registration Statement and shall remain in
     full force and effect, regardless of any termination or cancellation of
     this Agreement or any investigation made by or on behalf of any indemnified
     party.

     Section 8.  Liquidated Damages.
                 ------------------

          The Obligor and the Initial Purchasers agree that the Holders of
Transfer Restricted Securities will suffer damages if the Obligor fails to
fulfill its obligations under this Agreement and that it would not be feasible
to ascertain the extent of such damages with precision.  Accordingly, in the
event that, for any reason whatsoever:  (a) the Obligor fails to file any of the
Registration Statements required by this Agreement on or before the date
specified for such filing; (b) any of such Registration Statements is not
declared effective by the Commission on or prior to the date specified for such
effectiveness (the "Effectiveness Target Date"); (c) the Obligor fails to
                    -------------------------
consummate the Exchange Offer within 30 Business Days of the Effectiveness
Target Date with respect to the Exchange Offer Registration Statement; or (d)
the Shelf Registration Statement or the Exchange Offer Registration Statement is
declared effective but thereafter ceases to be effective or usable in connection
with resales of Transfer Restricted Securities during the periods specified in
this Agreement (each such event referred to in clauses (a) through (d) above a
"Registration Default"), then the Obligor will pay, as the exclusive remedy and
---------------------
in lieu of any other damages, liquidated damages ("Liquidated Damages") to each
                                                   ------------------
Holder of Notes, with respect to the first 90 calendar day period, or any
portion thereof, immediately following the occurrence of a Registration Default,
in an amount equal to 25 basis points per annum of the principal amount of Notes
held by such Holder.  The amount of the Liquidated Damages will increase by an
additional 25 basis points per annum of the principal amount of Notes with
respect to each subsequent 90 calendar day period, or any portion thereof, until
all Registration Defaults have been cured, up to a maximum amount of Liquidated
Damages of 100 basis points per annum of the principal amount of Notes.  At such
time as no Registration Default is continuing, the accrual of Liquidated Damages
will cease.  In the event of any Registration Default, the Obligor will provide
notice to the Trustee of such Registration Default, and will cause the Trustee
to provide appropriate notice thereof and of the imposition of the related
Liquidated Damages to the Holders of the Notes.

                                    - 21 -
<PAGE>

     Section 9.  Rule 144.
                 --------

          The Obligor agrees that to the extent it shall be required to do so
under the Exchange Act, the Obligor shall timely file the reports required to be
filed by it under the Exchange Act or the Securities Act (including, but not
limited to, the reports under Section 13 and 15(d) of the Exchange Act referred
to in subparagraph (c)(1) of Rule 144 under the Securities Act), and shall take
such further action as any Holder of Transfer Restricted Securities may
reasonably request, all to the extent required from time to time to enable such
Holder to sell Transfer Restricted Securities without registration under the
Securities Act within the limitations of the exemptions provided by Rule 144, as
such Rule may be amended from time to time, or any similar or successor rule or
regulation hereafter adopted by the Commission.  Upon the request of any Holder
of Transfer Restricted Securities in connection with the Holder's sale pursuant
to Rule 144, the Obligor shall deliver to such Holder a written statement as to
whether it has complied with such requirements.

     Section 10. Miscellaneous.
                 -------------

          (a) Amendments and Waivers.  The provisions of this Agreement may not
              ----------------------
     be amended, modified or supplemented, and waivers or consents to departures
     from the provisions hereof may not be given, unless the Company and the
     Issuer have obtained the written consent of Holders of a majority in
     aggregate principal amount of Transfer Restricted Securities; provided that
     the provisions of Section 7 of this Agreement may not be amended, modified
     or supplemented, and waivers or consents to departures from the provisions
     thereof may not be given, unless the Obligor has obtained the written
     consent of each Indemnified Holder adversely affected thereby.

          (b) No Inconsistent Agreements.  The Company and the Issuer will not,
              --------------------------
     on or after the date of this Agreement, enter into any agreement with
     respect to their respective securities that is inconsistent with the rights
     granted to the Holders in this Agreement or otherwise conflicts with the
     provisions hereof.  The rights granted to the Holders hereunder are not
     inconsistent with the rights granted to the holders of the Company's or the
     Issuer's securities under any agreement in effect on the date hereof.

          (c) Notices.  All notices and other communications provided for or
              -------
     permitted hereunder shall be made in writing by hand-delivery, first-class
     mail (registered or certified, return receipt requested), or courier
     guaranteeing overnight delivery:

               (i)     if to a Holder, at the address set forth on the records
          of the Registrar under the Indenture, with a copy to the Registrar
          under the Indenture; and

               (ii)    if to the Initial Purchasers, the Company or the Issuer,
          at their respective addresses set forth in the Purchase Agreement.

     All such notices and communications shall be deemed to have been duly
     given: at the time delivered by hand, if personally delivered; three
     Business Days after being

                                    - 22 -
<PAGE>

     deposited in the mail, postage prepaid, if mailed; and on the day
     delivered, if sent by overnight air courier guaranteeing next day delivery.

     Copies of all such notices, demands or other communications shall be
     concurrently delivered by the Person giving the same to the Trustee at the
     address specified in the Indenture.

          (d) Successors and Assigns.  This Agreement shall inure to the benefit
              ----------------------
     of and be binding upon the successors and assigns of each of the parties,
     including, without limitation and without the need for an express
     assignment, subsequent Holders of Transfer Restricted Securities.

          (e) Counterparts.  This Agreement may be executed in any number of
              ------------
     counterparts and by the parties hereto in separate counterparts, each of
     which when so executed shall be deemed to be an original and all of which
     taken together shall constitute one and the same agreement.

          (f) Headings.  The headings in this Agreement are for convenience of
              --------
     reference only and shall not limit or otherwise affect the meaning hereof.

          (g) Governing Law.  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED
              -------------
     IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK FOR CONTRACTS MADE AND
     TO BE FULLY PERFORMED IN SUCH STATE AND WITHOUT REGARD TO THE PRINCIPLES OF
     CONFLICT OF LAWS THEREOF.

          (h) Submission to Jurisdiction. (i) Each of the Company and the
              --------------------------
     Issuer:

               (x) irrevocably submits to the jurisdiction of any New York State
     or federal court sitting in New York City and any appellate court from any
     thereof in any action or proceeding arising out of or relating to this
     Agreement or any other document delivered hereunder;

               (y) irrevocably agrees that all claims in respect of any such
     action or proceeding may be heard and determined in such New York State
     court or in such federal court; and

               (z) irrevocably waives, to the fullest extent permitted by law,
     the defense of an inconvenient forum to the maintenance of such action or
     proceeding and irrevocably consents, to the fullest extent permitted by
     law, to service of process of any of the aforementioned courts in any such
     action or proceeding by the mailing of copies thereof by registered or
     certified mail, postage prepaid, to the Company or the Issuer, as
     applicable, at its address as provided in Section 10(c) of this Agreement,
     such service to become effective five days after such mailing;

                                    - 23 -
<PAGE>

               (ii)    Nothing in this Section shall affect the right of any
     person to serve legal process in any other manner permitted by law or
     affect the right of any person to bring any action or proceeding against
     the Company or the Issuer or their respective properties in the courts of
     other jurisdictions.

          (i) Severability.  In the event that any one or more of the provisions
              ------------
     contained herein, or the application thereof in any circumstance, is held
     invalid, illegal or unenforceable, the validity, legality and
     enforceability of any such provision in every other respect and the
     remaining provisions contained herein shall not, to the fullest extent
     permitted by law, be affected or impaired thereby.

          (j) Third Party Beneficiaries.  Holders of the Notes and Registered
              -------------------------
     Notes and each Indemnified Holder are intended third party beneficiaries of
     this Agreement and this Agreement may be enforced by such persons.

          (k) Entire Agreement.  This Agreement, together with the Purchase
              ----------------
     Agreement, is intended by the parties as a final expression of their
     agreement and is intended to be a complete and exclusive statement of the
     agreement and understanding of the parties hereto in respect of the subject
     matter contained herein.  There are no restrictions, promises. warranties
     or undertakings, other than those set forth or referred to herein, with
     respect to the registration rights granted by the Company and the Issuer
     with respect to the Transfer Restricted Securities.  This Agreement
     supersedes all prior agreements and understandings between the parties with
     respect to such subject matter.

                                    - 24 -
<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first written above.


                                        ARCH COMMUNICATIONS, INC.



                                        By: /s/ C.E. Baker, Jr.
                                           ----------------------------------
                                           Name: C.E. Baker, Jr.
                                           Title: Chairman of the Board
                                                  and Chief Executive Officer

                                        ARCH ESCROW CORP.


                                        By: /s/ C.E. Baker, Jr.
                                           ----------------------------------
                                           Name: C.E. Baker, Jr.
                                           Title: Chairman of the Board
                                                  and Chief Executive Officer


                                        BEAR, STEARNS & CO. INC.


                                        By: /s/ James C. Diao
                                           ----------------------------------
                                           Name: James C. Diao
                                           Title: Senior Managing Director

                                        TD SECURITIES (USA) INC.


                                        By: /s/ Gordon Paris
                                           ----------------------------------
                                           Name: Gordon Paris
                                           Title: Managing Director

                                        BNY CAPITAL MARKETS, INC.


                                        By: /s/ John M. Roy
                                           ----------------------------------
                                           Name: John M. Roy
                                           Title:

<PAGE>

                                        RBC DOMINION SECURITIES CORPORATION



                                        By: /s/ Donald W. Graham
                                           --------------------------------
                                        Name: Donald W. Graham
                                        Title: Vice President


                                        BARCLAYS CAPITAL INC.



                                        By:/s/ Michael Bloom
                                           --------------------------------
                                        Name: Michael Bloom
                                        Title: Director