EX-4.O
                          STOCK REGISTRATION STATEMENT


                                                            EXHIBIT B TO ANNEX A

                          STOCK REGISTRATION AGREEMENT

     This Stock Registration Agreement dated               , 1997 (this
"Registration Agreement"), is among Rollins Environmental Services, Inc., a
Delaware corporation ("Rollins"), Laidlaw Transportation, Inc., a Delaware
corporation ("LTI") and Laidlaw Inc., a Canadian corporation ("Laidlaw" and
together with LTI, the "Laidlaw Parties").

                              W I T N E S S E T H:

     WHEREAS, under a Stock Purchase Agreement dated as of               , 1997
(the "Stock Purchase Agreement"), among Rollins and the Laidlaw Parties, Rollins
is this date issuing to LTI (i) 120,000,000 shares (the "Rollins Common Shares")
of Common Stock, $1.00 par value per share (the "Common Stock"), of Rollins and
(ii) a 5%, 12 year $350 million principal amount, convertible, pay-in-kind
debenture (the "Rollins Convertible Debenture"), which is convertible into
shares of Common Stock and pursuant to which interest and principal payments can
be made in shares of Common Stock (collectively, the "Additional Rollins Common
Shares");

     WHEREAS, the Stock Purchase Agreement requires that this Registration
Agreement be entered into among Rollins and the Laidlaw Parties upon the
issuance to the Laidlaw Parties of such securities of Rollins; and

     WHEREAS, the parties hereto (the "Parties") deem it desirable to enter into
this Registration Agreement to establish certain rights and restrictions with
respect to the management of the Company and the voting, sale and registration
of the shares of Common Stock,

     NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Parties agree that:

                                   ARTICLE I
                                  DEFINITIONS

     1.1. Definitions.  In this Registration Agreement:

          "Affiliate" means, with respect to any Person, another Person that
     directly, or indirectly through one or more intermediaries, controls, is
     controlled by or is under common control with such Person, with the terms
     "control" and "controlled" meaning, for purposes of this definition, the
     power to direct the management and policies of a Person, directly or
     indirectly, whether through the ownership of voting securities or
     partnership or other ownership interests, or by contract or otherwise.

          "Canadian Securities Acts" means the applicable securities legislation
     of each of the provinces and territories of Canada, and the regulations,
     rules and policies made thereunder or issued by the Commissions
     administering such legislation, as the same may hereafter be amended or
     replaced.

          "Commissions" means the securities commissions or similar regulatory
     authorities of each of the provinces and territories of Canada and any
     successor regulatory authorities having similar powers.

          "Designated Jurisdictions" has the meaning specified in Section 2.2.

          "Elected Jurisdictions" has the meaning specified in Section 2.1.

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

          "Inspectors" has the meaning specified in Section 2.4.



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          "Offering Expenses" means all expenses incidental to Rollins's
     performance of or compliance with its obligations under Section 2.2 in
     connection with the qualification by prospectus of Registrable Securities
     under any of the Canadian Securities Acts, including, without limitation,
     all filing fees, all fees and expenses of complying with the applicable
     Canadian Securities Acts, all printing and translation expenses, all fees
     and disbursements of counsel to any Laidlaw Party and all fees and
     disbursements of Canadian counsel to Rollins and any underwriting fees and
     commissions and applicable transfer taxes, if any, relating to the
     distribution of the Registrable Securities under any Canadian Securities
     Acts.

          "Offering Notice" has the meaning specified in Section 4.4.

          "Offering Registration Statement" has the meaning specified in Section
     4.4.

          "Offering Termination Date" has the meaning specified in Section 4.4.

          "Person" means an individual, corporation, partnership, association,
     joint stock company, limited liability company, governmental entity,
     business trust, unincorporated organization or other legal entity.

          "Registrable Securities" means (i) the Rollins Common Shares, (ii) the
     Rollins Convertible Debenture, (iii) the Additional Rollins Common Shares
     and (iv) any shares of Common Stock issued in connection with any stock
     dividend on, or any stock split, reclassification or reorganization of,
     shares of Common Stock referenced in subparagraphs (i), (ii) or (iii)
     above.

          "SEC" means the United States Securities and Exchange Commission or
     any successor agency.

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

          "Selling Laidlaw Party" has the meaning specified in Section 2.4.

          "Specified Securities" has the meaning specified in Section 2.1.

                                   ARTICLE II
                              REGISTRATION RIGHTS

     2.1. Incidental Rights.  If at any time or from time to time Rollins
proposes to file (i) with the SEC a registration statement (whether on Form S-1,
S-2, or S-3, or any equivalent form then in effect) for the registration under
the Securities Act of any shares of Common Stock for sale, or (ii) a prospectus
under any of the Canadian Securities Acts in order to qualify a distribution
under any of the Canadian Securities Acts of any securities, for cash
consideration, to the public by Rollins or on behalf of one or more shareholders
of Rollins (excluding any sale of securities convertible into or exercisable for
Common Stock, and any shares of Common Stock issuable by Rollins upon the
exercise of employee stock options, or to any employee stock ownership plan, or
in connection with any acquisition made by Rollins, any securities exchange
offer, dividend reinvestment plan, employee benefit plan, corporate
reorganization, or in connection with any amalgamation, merger or consolidation
of Rollins with one or more other corporations if Rollins is the surviving
corporation), Rollins shall give the Laidlaw Parties at least 20 days' prior
written notice of the proposed filing (or if 20 days' notice is not practicable,
a reasonable shorter period of not less than seven days), which notice shall
outline the nature of the proposed distribution and the U.S. and Canadian
jurisdictions in which Rollins proposes to qualify and offer such securities
(the "Elected Jurisdictions"). On the written request of a Laidlaw Party
received by Rollins within 15 days (or within 7 days if 20 days' notice cannot
practicably be given by Rollins) after the date of Rollins's delivery to the
Laidlaw Parties of the notice of intended registration (which request shall
specify the Registrable Securities sought to be disposed of by each Laidlaw
Party and the intended method or methods by which dispositions are intended to
be made), Rollins shall, under the terms and subject to the conditions of this
Article II, at its own expense as provided in Section 4.2, (a) use its
reasonable efforts to include in the coverage of



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such U.S. registration statement (or in a separate U.S. registration statement
concurrently filed) and qualify for sale under the blue sky or securities laws
of the various states, and (b) use its reasonable efforts to effect the
qualification under the Canadian Securities Acts, in the Elected Jurisdictions
the number of Registrable Securities (herein called the "Specified Securities")
held by such Laidlaw Party and which such Laidlaw Party has so requested to be
registered or qualified for distribution, to the extent required to permit the
distribution (in accordance with the intended method or methods thereof as
aforesaid) in the Elected Jurisdictions requested by such Laidlaw Party of such
Registrable Securities.

     If the distribution proposed to be effected by Rollins involves an
underwritten offering of the securities being so distributed by or through one
or more underwriters, and if the managing underwriter of such underwritten
offering indicates in writing its reasonable opinion that including all or part
of the Specified Securities in the coverage of such registration statement or in
the distribution to be effected by such prospectus will materially and adversely
affect the sale of securities proposed to be sold (which statement of the
managing underwriter shall also state the maximum number of shares, if any,
which can be sold by the Laidlaw Party requesting registration under this
Section 2.1 without materially and adversely affecting the sale of the shares
proposed to be sold), then the number of Specified Securities which the
requesting Laidlaw Party shall have the right to include in such registration
statement or to have qualified by such prospectus shall be reduced to the
maximum number of shares specified by the managing underwriter. In all cases,
priority shall be afforded to securities covered by a registration statement
and/or qualified for distribution by a prospectus filed in response to the
exercise of a demand registration or qualification right by a holder of Common
Stock other than a holder exercising rights under this Registration Agreement
and no securities proposed to be sold by such other holder shall be so reduced
until all securities proposed to be sold by all other parties have been entirely
eliminated. As to all other proposed selling shareholders of Common Stock,
including the Laidlaw Party requesting to include Registrable Securities in the
coverage of such a registration statement or prospectus, any such reduction in
the number of shares of Common Stock proposed to be sold by the selling
shareholders shall be effected on a pro rata basis in accordance with the
relationship which the number of shares of Common Stock proposed to be sold by
each selling shareholder bears to the number of shares of Common Stock proposed
to be sold by all selling shareholders.

     Rollins shall have the sole right to select any underwriters, including the
managing underwriter, of any public offering of shares of Common Stock subject
to this Section 2.1.

     Each Laidlaw Party may request to have Common Stock included in an
unlimited number of registrations, and qualified by an unlimited number of
prospectuses, under this Section 2.1. Registration rights under this Section 2.1
shall extend only to the incidental registrations of Common Stock.

     2.2. Mandatory Rights.  Upon written request of a Laidlaw Party made at any
time, Rollins shall, under the terms and subject to the conditions set forth in
this Section 2.2 and in Section 2.4, (i) at Rollins' expense, file (and use its
reasonable efforts to cause to become effective) a U.S. registration statement
covering, and use its reasonable efforts to qualify for sale under the blue sky
or securities laws of the various U.S. states as may be requested by such
Laidlaw Party (except any such state in which, in the opinion of the managing
underwriter of the offering, the failure to so qualify would not materially and
adversely affect the proposed offering), and (ii) at such Laidlaw Party's
expense, use its reasonable efforts to effect the qualification for distribution
under the Canadian Securities Acts, in accordance with the intended method or
methods of disposition set forth in that notice, such number of Registrable
Securities, as may be designated by such Laidlaw Party in its request, or that
portion thereof designated in said request for registration or qualification in
each of the Designated Jurisdictions (as defined below). A request for
registration under this Section 2.2 shall specify the number of shares to be
registered, the United States and Canadian jurisdiction in which such
registration or qualification is to be effected (the "Designated Jurisdictions")
and the proposed manner of sale, including the name and address of any proposed
underwriter; provided, that all offerings contemplated by a request for
registration under this Section 2.2 shall be underwritten offerings involving
either a distribution of Registrable Shares to the public where no single buyer,



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<PAGE>


acting individually or with others, acquires more than 10% of such offering, or
a distribution by way of dividend or other distribution to holders of Common
Stock in the capital of Rollins where such dividend or other distribution is
made pro rata between the holders of all such classes of shares according to the
number of shares of either class held by each of them. The principal underwriter
or underwriters for any such offering shall be selected by the Laidlaw Party
requiring registration, subject to Rollins's approval, which may not
unreasonably be withheld.

     If the distribution proposed to be effected pursuant to this Section 2.2
involves an underwritten offering of the securities being so distributed by or
through one or more underwriters, and if the managing underwriter of such
underwritten offering indicates in writing its reasonable belief that including
all or part of the Registrable Securities in the coverage of such registration
statement or in the distribution to be effected by such prospectus will
materially and adversely affect the sale of the securities proposed to be sold,
then the number of securities proposed to be sold shall be reduced to the
maximum number of securities specified by the managing underwriter. In such a
case, priority shall be afforded to Registrable Securities and the securities
that are not Registrable Securities shall be completely eliminated from
inclusion in such offering before the number of Registrable Securities is
reduced.

     Rollins may delay the filing or effectiveness of any registration
statement, or any preliminary prospectus or (final) prospectus required to
effect a qualification for distribution, requested under this Section 2.2, or
delay its effectiveness, for a reasonable period (but not longer than 120 days)
if, in the sole judgment of Rollins's Board of Directors, (i) a delay is
necessary in light of pending financing transactions, corporate reorganizations
or other major events involving Rollins, or (ii) filing at the time requested
would materially and adversely affect the business or prospects of Rollins in
view of disclosures that may thereby be required. Once the cause of the delay is
eliminated, Rollins shall promptly notify the Laidlaw Parties requiring
registration or qualification, and promptly after a Laidlaw Party notifies
Rollins to proceed, Rollins shall, as required in connection with the Designated
Jurisdictions selected by the relevant Laidlaw Parties, file a registration
statement or a preliminary prospectus and/or (final) prospectus and begin
performance of its other obligations under this Section 2.2.

     The Laidlaw Parties shall be entitled to request three registrations or
qualifications under this Section 2.2 from the date hereof until the fifth
anniversary of the date hereof and three additional registrations or
qualifications under this Section 2.2 from the fifth anniversary of the date
hereof until the twelfth anniversary of the date hereof (provided that the
filing of a registration statement and a preliminary prospectus or (final)
prospectus in more than one Designated Jurisdictions in connection with a
concurrent or substantially concurrent distribution shall be deemed for the
purposes hereof to be a single registration and qualification). However, if a
Laidlaw Party requests a registration under this Section 2.2, but no
registration statement or (final) prospectus becomes effective with respect to
the Registrable Securities covered by such request, then such request shall not
count as a request for purposes of determining the number of requests for
registration or qualification the Laidlaw Parties may make under this Section
2.2.

     2.3. Registration Conditions.  Notwithstanding any other provision of this
Registration Agreement, Rollins shall not be required to effect a registration
or qualification of any securities under this Article II, or file any
post-effective amendment to such a registration statement or prospectus relating
to such a qualification:

          2.3.1. unless the requesting Laidlaw Party agrees to (a) sell and
     distribute a portion or all of its Registrable Securities in accordance
     with the plan or plans of distribution adopted by and through underwriters,
     if any, acting for Rollins, and (b) bear a pro rata share of underwriter's
     discounts and commissions;

          2.3.2. if a registration or qualification requested under Section 2.2,
     or any post-effective amendment to the registration statement and/or
     prospectus filed in connection therewith, requires, under applicable
     statutes and rules, a special audit (other than a normal fiscal year-end
     audit) of any financial statements, unless the requesting Laidlaw Party
     agrees to pay its proportionate share



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     (determined by the number of shares to be sold by such Laidlaw Party in the
     offering in proportion to the total number of shares to be sold by Rollins
     and all other participants in such offering) of the reasonable fees and
     expenses of accountants incurred in connection with the special audit and
     which would otherwise not be incurred;

          2.3.3. if, in the case of a request for registration or qualification
     under Section 2.1 or 2.2, in the reasonable opinion of counsel for Rollins,
     (i) the Registrable Securities for which registration under the Securities
     Act has been requested may be disposed of without adversely affecting the
     market price of such Registrable Securities within a comparable time frame
     without registration under the Securities Act and (ii) upon such
     disposition all legends on certificates representing such shares which
     restrict their transfer under the Securities Act and applicable state
     securities laws may be removed, and the sale by the applicable Laidlaw
     Party of any Registrable Securities for which qualification for
     distribution under any Canadian Securities Acts has been requested (a) will
     not constitute a "distribution" (or the corresponding term) under the
     applicable Canadian Securities Acts, or (b) may be effected in the method
     requested (or in a method having a substantially similar economic effect,
     as to which such counsel may make any reasonable assumption for the
     purposes of such opinion) without qualification by prospectus; provided
     that the first trade of such Registrable Securities by the purchaser
     thereof from the Laidlaw Party in such sale would not constitute a
     "distribution" (or the corresponding term) under the applicable Canadian
     Securities Acts (but for (I) any unusual effort made to prepare the market
     or to create a demand for such securities made by or on behalf of such
     purchaser), (II) any extraordinary commission or consideration paid or to
     be paid in respect of such first trade, or (III) such purchaser being a
     Person described in clause (III) of the definition of "distribution" set
     forth in section 1(1) of the Securities Act (Ontario) in relation to
     Rollins (or any corresponding provision of any other applicable Canadian
     Securities Act);

          2.3.4. if, in the case of a request for registration under Section
     2.2, other than with respect to a distribution by way of dividend or other
     distribution to holders of common stock in the capital of Laidlaw where
     such dividend or other distribution is made pro rata between the holders of
     all such classes of shares according to the number of shares of either
     class held by each of them (i) any registration statement or prospectus
     covering securities regarding which a Laidlaw Party could have exercised
     registration rights under Section 2.1 of this Registration Agreement has
     become effective under the Securities Act or, with respect to a (final)
     prospectus, a receipt has been issued therefor under the applicable
     Canadian Securities Acts within six months preceding the date of such
     request, (ii) a registration statement or prospectus requested by a Laidlaw
     Party pursuant to Section 2.2 has become effective under the Securities Act
     or, with respect to a (final) prospectus, a receipt has been issued
     therefor under the applicable Canadian Securities Acts within twelve months
     preceding the date of such request or (iii) Rollins has given notice under
     Section 2.1 of its intention to file a registration statement under the
     Securities Act or a prospectus under any Canadian Securities Acts and has
     not completed or abandoned the proposed offering; and

          2.3.5. unless Rollins has received from the Laidlaw Party requesting
     registration or qualification all information Rollins has reasonably
     requested concerning such Laidlaw Party and its method of distribution of
     its Registrable Securities, so as to enable Rollins to include in the
     registration statement or prospectus all facts required to be disclosed in
     it.

     2.4. Covenants and Procedures.  If Rollins becomes obligated under this
Article II to effect a registration or qualification of Registrable Securities
on behalf of a Laidlaw Party requesting registration or qualification under this
Article II (hereinafter called a "Selling Laidlaw Party"), then (as applicable
to the jurisdictions for which such registration or qualification is to be
made):

          2.4.1. Rollins, (i) at its expense as provided in Section 4.2, shall
     prepare and file with the SEC a registration statement covering and, as
     applicable, (ii) at its expense as provided in Section 4.2 if such
     registration is triggered pursuant to Section 2.1, or at the expense of the
     requesting Selling Laidlaw Party as provided in Section 4.3 if such
     registration is triggered pursuant to



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     Section 2.2, prepare and file with the applicable Commissions (in the
     English and French languages, as applicable) a preliminary prospectus
     qualifying such securities and such other related documents as may be
     necessary or appropriate relating to the proposed distribution, and shall
     use reasonable efforts to cause the registration statement to become
     effective and (with respect to Canadian jurisdictions) after any comments
     of the Commissions have been satisfied with respect thereto, to prepare and
     file in accordance with the relevant Canadian Securities Acts, a (final)
     prospectus in the English and French languages, as appropriate, and receive
     receipts therefor and shall take all other steps and proceedings that may
     be necessary in order to qualify the applicable Registrable Securities for
     distribution under such Canadian Securities Acts by registrants who comply
     with the relevant provisions of such Canadian Securities Acts. Rollins will
     also (a) with respect to any U.S. registration statement, file such
     post-effective amendments to the registration statement (and use reasonable
     efforts to cause it to become effective) and such supplements as are
     necessary so that current prospectuses are at all times available for a
     period of at least 90 days after the effective date of the registration
     statement or for such longer period, not to exceed 180 days, as may be
     required under the plan or plans of distribution set forth in the
     registration statement, and (b) with respect to any Canadian prospectus,
     file with the Commissions such amendments and supplements to such
     preliminary prospectus and (final) prospectus as may be necessary to comply
     with the provisions of the Canadian Securities Acts applicable to the
     proposed distribution until the earlier of (I) such time as all of
     Registrable Securities proposed to be sold thereunder have been disposed of
     in accordance with the intended method or methods of disposition by the
     Selling Laidlaw Party thereof, and (II) the expiration of a period of at
     least 90 days after the issuance by the Commissions in all applicable
     Canadian jurisdictions for the (final) prospectus or such longer period,
     not to exceed 180 days, as may be required under the plan or plans of
     distribution set forth in such (final) prospectus. Each Selling Laidlaw
     Party shall promptly provide Rollins with such information with respect to
     such Selling Laidlaw Party's Registrable Securities to be so registered and
     qualified and, if applicable, the proposed terms of their offering, as is
     required for the registration or qualification. If the Registrable
     Securities to be covered by the registration statement and/or prospectus
     are not to be sold to or through underwriters acting for Rollins, Rollins
     shall:

             (x) deliver to each Selling Laidlaw Party, as promptly as
        practicable, as many copies of preliminary prospectuses as each Selling
        Laidlaw Party may reasonably request (in which case each Selling Laidlaw
        Party shall keep a written record of the distribution of the preliminary
        prospectuses and shall refrain from delivery of the preliminary
        prospectuses in any manner or under any circumstances which would
        violate the Securities Act, the applicable Canadian Securities Acts or
        the securities laws of any other jurisdiction, including the various
        states of the United States);

             (y) deliver to each Selling Laidlaw Party, as soon as practicable
        after the effective date of the U.S. registration statement, or, as
        applicable, the date on which all applicable Commissions shall have
        issued a receipt for the Canadian (final) prospectus, and from time to
        time thereafter during the applicable period described in paragraph
        2.4.1(i) or (ii), as many copies of the relevant prospectuses (including
        any (final) prospectus as such Selling Laidlaw Party may reasonably
        request); and

             (z) in case of the happening, after the effective date of the
        registration statement and during the applicable 90 or 180 day period
        described in the second sentence of paragraph 2.4.1, of any event or
        occurrence as a result of which the prospectus (including any
        preliminary prospectus or (final) prospectus), as then in effect, would
        include an untrue statement of a material fact or omit to state any
        material fact required to be stated therein or necessary to make any
        statement therein not misleading in the light of the circumstances in
        which it was made, give each Selling Laidlaw Party written notice of the
        event or occurrence and prepare and furnish to each Selling Laidlaw
        Party, in such quantities as it may reasonably request, copies of an
        amendment of or a supplement to such prospectus as may be necessary so
        that the prospectus, as so amended or supplemented and thereafter
        delivered to



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        purchasers of the securities, will not contain any untrue statement of a
        material fact or omit to state any 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.

          2.4.2. Rollins will notify each Selling Laidlaw Party of any action by
     the SEC or any Commission to suspend the effectiveness of any registration
     statement or prospectus filed pursuant hereto or the initiation or
     threatened initiation of any proceeding for such purpose or the receipt by
     Rollins of any notification with respect to the suspension of the
     qualification of the securities covered by a prospectus filed pursuant
     hereto for sale in any jurisdiction. Immediately upon receipt of any such
     notice, the Laidlaw Parties shall cease to offer or sell any Registrable
     Securities pursuant to the registration statement or prospectus in the
     jurisdiction to which such order or suspension relates. Rollins will also
     notify each Selling Laidlaw Party promptly of the occurrence of any event
     or the existence of any state of facts that, in the judgment of Rollins,
     should be set forth in such registration statement or prospectus.
     Immediately upon receipt of such notice, the Laidlaw Parties shall cease to
     offer or sell any Registrable Securities pursuant to such registration
     statement or prospectus, cease to deliver or use such registration
     statement or prospectus and, if so requested by Rollins, return to Rollins
     at Rollins's expense all copies of such registration statement or
     prospectus. Rollins will as promptly as practicable take such action as may
     be necessary to amend or supplement such registration statement or
     prospectus in order to set forth or reflect such event or state of facts
     and provide copies of such proposed amendment or supplement to each Selling
     Laidlaw Party.

          2.4.3. On or before the date on which the registration statement is
     declared effective, or a receipt is issued by all Commissions for the
     (final) prospectus, Rollins shall use its reasonable efforts to:

             (i) register or qualify (and cooperate with each Selling Laidlaw
        Party, the underwriter or underwriters, if any, and their counsel, in
        connection with the registration or qualification of) the securities
        covered by the registration statement for offer and sale under the
        securities or blue sky laws of each state and other U.S. or Canadian
        jurisdiction as any Selling Laidlaw Party or underwriter reasonably
        requests;

             (ii) use its reasonable efforts to keep each such registration or
        qualification effective, including through new filings, or amendments or
        renewals, during the period the registration statement or prospectus is
        required to be kept effective; and

             (iii) do any and all other acts or things necessary or advisable to
        enable the disposition in all such jurisdictions of the Common Stock
        covered by the applicable registration statement or prospectus, provided
        that Rollins will not be required to qualify generally to do business in
        any jurisdiction where it is not then so qualified.

          2.4.4. Rollins shall use its reasonable efforts to cause all
     Registrable Securities of a Selling Laidlaw Party included in the
     registration statement or qualified by prospectus to be listed, by the date
     of the first sale of such shares pursuant to such registration statement or
     prospectus, on each securities exchange on which the securities as then
     listed or proposed to be listed, if any.

          2.4.5. Rollins shall make generally available to each Selling Laidlaw
     Party and any underwriter participating in the offering conducted pursuant
     to the registration statement an earnings statement satisfying Section
     11(a) of the Securities Act no later than 45 days after the end of the
     12-month period beginning with the first day of Rollins's first fiscal
     quarter commencing after the effective date of the registration statement.
     The earnings statement shall cover such 12-month period. This requirement
     will be deemed to be satisfied if Rollins timely files complete and
     accurate information on Forms 10-Q, 10-K and 8-K under the Exchange Act,
     and otherwise complies with Rule 158 under the Securities Act as soon as
     practicable. In addition, in the event that Rollins shall have become a
     reporting issuer (or have the corresponding status) under any of the
     Canadian Securities Acts, Rollins shall comply with the continuous
     disclosure



                                      A-B-7
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     obligations of a reporting issuer (or the obligations attendant upon such
     corresponding status) prescribed by each Canadian Securities Act under
     which it has such status.

          2.4.6. Rollins shall cooperate with each Selling Laidlaw Party and the
     managing underwriter or underwriters, if any, to facilitate the timely
     preparation and delivery of certificates (not bearing any restrictive
     legends) representing Registrable Securities to be sold under the
     registration statement or prospectus, and to enable such securities to be
     in such denominations and registered in such names as the managing
     underwriter or underwriters, if any, or the Selling Laidlaw Party, may
     request, subject to the underwriters' obligation to return any certificates
     representing unsold securities.

          2.4.7. Rollins shall use its reasonable efforts to cause Registrable
     Securities covered by the registration statement or prospectus to be
     registered with or approved by such other governmental agencies or
     authorities in the U.S. or Canada (including the registration of
     Registrable Securities under the Exchange Act) as may be necessary to
     enable the Selling Laidlaw Parties or the underwriter or underwriters, if
     any, to consummate the disposition of such securities.

          2.4.8. Rollins shall, during normal business hours and upon reasonable
     notice, make available for inspection by each Selling Laidlaw Party, any
     underwriter participating in any offering pursuant to the registration
     statement or prospectus, and any attorney, accountant or other agent
     retained by a Selling Laidlaw Party or any such underwriter (collectively,
     the "Inspectors"), all nonconfidential financial and other records,
     pertinent corporate documents, and properties of Rollins, as shall be
     reasonably necessary to enable the Inspectors to exercise their due
     diligence responsibilities and as they may reasonably consider to be
     necessary for the purpose of establishing their due diligence defense (as
     applicable) as contemplated by the Canadian Securities Acts and in order to
     enable any such underwriters to execute the certificate on any prospectus
     required pursuant to any Canadian Securities Acts to be executed by them.
     Rollins shall also cause its officers, directors, and employees to supply
     all nonconfidential information reasonably requested by any Inspector in
     connection with the registration statement.

          2.4.9. Rollins shall use its reasonable efforts to obtain a "cold
     comfort" letter and, as applicable, a "long-form comfort letter" from
     Rollins's independent public accountants, and an opinion of counsel for
     Rollins, each in customary form and covering such matters of the type
     customarily covered by cold comfort letters and long form comfort letters
     and legal opinions in connection with public offerings of securities, as
     the Selling Laidlaw Party reasonably requests, and consents from all
     parties from whom such consents would be required under the applicable
     Canadian Securities Acts.

          2.4.10. Rollins shall provide and cause to be maintained a transfer
     agent and registrar for all Registrable Securities for the term of this
     Registration Agreement.

          2.4.11. Rollins shall use all reasonable efforts to cause the
     Registrable Securities covered by the registration statement to continue to
     be listed for a period of three years after the registration statement is
     declared effective on at least one national securities exchange on which
     the Common Stock is listed.

          2.4.12. Rollins shall reasonably cooperate, at the Selling Laidlaw
     Party's expense, with the Selling Laidlaw Party participating in the
     disposition of the Registrable Securities and its respective counsel in
     connection with any filings required to be made with the National
     Association of Securities Dealers, Inc.

          2.4.13. Rollins shall make available to the managing underwriters
     certain of its officers (subject to the reasonable demands of its business)
     for the purpose of participating in one "road show" presentation in
     connection with underwritten offerings. The Selling Laidlaw Parties agree
     that they will bear all incremental expenses incurred by Rollins in
     complying with this Section 3.4.13 if such registration is triggered
     pursuant to a request under Section 2.2.



                                      A-B-8
<PAGE>


          2.4.14. Rollins shall enter into such customary agreements (including,
     if applicable, an underwriting agreement) and take such other actions as
     each Selling Laidlaw Party shall reasonably request in order to expedite or
     facilitate the disposition of the Registrable Securities; provided that
     such customary agreements, if any, shall be reasonably satisfactory in form
     and substance to Rollins. Laidlaw shall be a party to such underwriting
     agreement and may, at its option, require that Rollins make to and for the
     benefit of Laidlaw the representations, warranties and covenants of Rollins
     which are being made to and for the benefit of such underwriters and which
     are of the type customarily provided to institutional investors in
     secondary offerings.

          2.4.15. Rollins shall deliver promptly to Laidlaw and each
     underwriter, if any, copies of all correspondence between the SEC, on the
     one hand, and Rollins, its counsel or auditors, on the other hand, and all
     memoranda relating to discussions with the SEC or its staff, with respect
     to any registration statement, other than those portions of any such
     correspondence and memoranda which contain information subject to
     attorney-client privilege with respect to Rollins, and, upon receipt of
     such confidentiality agreements as Rollins may reasonably request, make
     reasonably available for inspection by any Selling Laidlaw Party covered by
     such registration statement, by any underwriter, if any participating in
     any disposition to be effected pursuant to such registration statement and
     by any attorney, accountant or other agent retained by any Selling Laidlaw
     Party or any such underwriter, all pertinent financial and other records,
     pertinent corporate documents and properties of Rollins, and cause all of
     Rollins' officers, directors and employees to supply all information
     reasonably requested by any such Selling Laidlaw Party, underwriter,
     attorney, accountant or agent in connection with such registration
     statement.

                                  ARTICLE III
                                INDEMNIFICATION

     3.1. Indemnification by Rollins.  In the event of any registration or
qualification under the Securities Act or any Canadian Securities Act by any
registration agreement or prospectus pursuant to rights herein granted of
Registrable Securities held by a Laidlaw Party who becomes a Selling Laidlaw
Party, Rollins will hold harmless such Selling Laidlaw Party and each
underwriter of such securities and each other Person, if any, who controls such
Selling Laidlaw Party or such underwriter within the meaning of the Securities
Act, against any losses, claims, damages or liabilities (including legal fees
and costs of court), joint or several, to which such Selling Laidlaw Party or
such underwriter or controlling Person becomes subject under the Securities Act,
the applicable Canadian Securities Acts or otherwise, insofar as such losses,
claims, damages or liabilities (or any actions in respect thereof) arise out of
or are based upon any untrue statement or alleged untrue statement of any
material fact contained, on its effective date, in any registration statement
under which such securities were registered under the Securities Act, or in any
related preliminary or (final) prospectus, or in any preliminary prospectus or
(final) prospectus under which such securities were qualified for distribution
under any Canadian Securities Act, or any amendment or supplement to any of the
foregoing, or which arise out of or are based upon the omission or alleged
omission to state a material fact required to be stated therein or necessary to
make the statements therein not misleading; and will reimburse such Selling
Laidlaw Party and each such underwriter and each such controlling Person for any
legal or any other expenses reasonably incurred by them in connection with
investigating or defending any such loss, claim, damage or liability; provided,
however, that Rollins shall not be liable to such Selling Laidlaw Party or its
underwriters or controlling Persons in any such case to the extent that any such
loss, claim, damage or liability arises out of or is based upon an untrue
statement or alleged untrue statement or omission or alleged omission made in
such registration statement, preliminary or (final) prospectus or such amendment
or supplement, in reliance upon and in conformity with information furnished to
Rollins through a written instrument duly executed by such Selling Laidlaw Party
or such underwriter specifically for use in the preparation thereof or results
from any improper conduct of such Selling Laidlaw Party or any such underwriter
or controlling Person.



                                      A-B-9
<PAGE>


     3.2. Indemnification by Selling Laidlaw Parties.  It shall be a condition
precedent to the obligation of Rollins to include in any registration statement
or to qualify by prospectus any Registrable Securities of a Selling Laidlaw
Party that Rollins shall have received from such Selling Laidlaw Party an
undertaking, reasonably satisfactory to Rollins and its counsel, to indemnify
and hold harmless (in the same manner and to the same extent as set forth in
Section 4.1) Rollins, each director of Rollins, each officer of Rollins who
shall sign the registration statement or prospectus and any Person who controls
Rollins within the meaning of the Securities Act, (i) with respect to any
statement or omission from such registration statement, any related preliminary
or (final) prospectus or any amendment or supplement to any of the foregoing, if
such statement or omission was made in reliance upon and in conformity with
information furnished to Rollins through a written instrument duly executed by
such Selling Laidlaw Party specifically for use in the preparation of such
registration statement, preliminary or (final) prospectus or amendment or
supplement and (ii) with respect to compliance by such Selling Laidlaw Party
with applicable laws in effecting the sale or other disposition of the
securities covered by such registration statement; provided, however, that the
aggregate amount which any such Selling Laidlaw Party shall be required to pay
pursuant to this Section 3.2 shall in no case be greater than the amount of the
net proceeds received by such Selling Laidlaw Party upon the sale of the
Registrable Securities pursuant to the registration statement giving rise to
such claim.

     3.3. Indemnification Procedures.  Promptly after receipt by an indemnified
party of notice of the commencement of any action involving a claim referred to
in the preceding Sections of this Article III, the indemnified party will, if a
resulting claim is to be made or may be made against an indemnifying party, give
written notice to the indemnifying party of the commencement of the action. If
any such action is brought against an indemnified party, the indemnifying party
will be entitled to participate in and to assume the defense of the action with
counsel reasonably satisfactory to the indemnified party, and after notice from
the indemnifying party to such indemnified party of its election to assume
defense of the action, the indemnifying party will not be liable to such
indemnified party for any legal or other expenses incurred by the latter in
connection with the action's defense. An indemnified party shall have the right
to employ separate counsel in any action or proceeding and participate in the
defense thereof, but the fees and expenses of such counsel shall be at such
indemnified party's expense unless (i) the employment of such counsel has been
specifically authorized in writing by the indemnifying party, which
authorization shall not be unreasonably withheld, (ii) the indemnifying party
has not assumed the defense and employed counsel reasonably satisfactory to the
indemnified party within 30 days after notice of any such action or proceeding
or (iii) the named parties to any such action or proceeding (including any
impleaded parties) include the indemnified party and the indemnifying party and
the indemnified party shall have been advised by such counsel that there may be
one or more legal defenses available to the indemnified party that are different
from or additional to those available to the indemnifying party (in which case
the indemnifying party shall not have the right to assume the defense of such
action or proceeding on behalf of the indemnified party), it being understood,
however, that the indemnifying party shall not, in connection with any one such
action or separate but substantially similar or related actions in the same
jurisdiction arising out of the same general allegations or circumstances, be
liable for the reasonable fees and expenses of more than one separate firm of
attorneys (in addition to all local counsel which is necessary, in the good
faith opinion of both counsel for the indemnifying party and counsel for the
indemnified party in order to adequately represent the indemnified parties) for
the indemnified party and that all such fees and expenses shall be reimbursed as
they are incurred upon written request and presentation of invoices. Whether or
not a defense is assumed by the indemnifying party, the indemnifying party will
not be subject to any liability for any settlement made without its consent. No
indemnifying party will consent to entry of any judgment or enter into any
settlement which does not include as an unconditional term the giving by the
claimant or plaintiff, to the indemnified party, of a release from all liability
in respect of such claim or litigation.

     3.4. Contribution.  If the indemnification required by this Article IV from
the indemnifying party is unavailable to or insufficient to hold harmless an
indemnified party in respect of any indemnifiable losses, claims, damages,
liabilities or expenses, then the indemnifying party shall



                                     A-B-10
<PAGE>


contribute to the amount paid or payable by the indemnified party as a result of
such losses, claims, damages, liabilities or expenses in such proportion as is
appropriate to reflect (i) the relative benefit of the indemnifying and
indemnified parties and (ii) if the allocation in clause (i) is not permitted by
applicable law, in such proportion as is appropriate to reflect the relative
benefit referred to in clause (i) and also the relative fault of the indemnified
and indemnifying parties, in connection with the actions which resulted in such
losses, claims, damages, liabilities or expenses, as well as any other relevant
equitable considerations. The relative fault of the indemnifying party and the
indemnified party shall be determined by reference to, among other things,
whether any action in question, including any untrue or alleged untrue statement
of a material fact, has been made by, or relates to information supplied by,
such indemnifying party or parties, and the parties' relative intent, knowledge,
access to information, and opportunity to correct or prevent such action. The
amount paid or payable by a party as a result of the losses, claims, damage,
liabilities and expenses referred to above shall be deemed to include any legal
or other fees or expenses reasonably incurred by such party in connection with
any investigation or proceeding. Rollins and the Laidlaw Parties agree that it
would not be just and equitable if contribution pursuant to this Section 3.4
were determined by pro rata allocation or by any other method of allocation
which does not take account of the equitable considerations referred to in the
prior provisions of this Section 3.4.

     Notwithstanding the provisions of this Section 3.4, no indemnifying party
shall be required to contribute any amount in excess of the amount by which the
total price at which the securities were offered to the public by the
indemnifying party exceeds the amount of any damages which the indemnifying
party has otherwise been required to pay by reason of an untrue statement or
omission. No Person guilty of fraudulent misrepresentation (within the meaning
of Section 11(f) of the Securities Act or the Criminal Code (Canada)) shall be
entitled to contribution from any Person who was not guilty of such a fraudulent
misrepresentation.

                                   ARTICLE IV
                                OTHER AGREEMENTS

     4.1. Other Registration Rights.  Rollins agrees that it will not grant to
any Person registration rights which would allow such Person to limit Laidlaw's
priority for the sale or distribution of Registrable Securities upon the
exercise of mandatory registration rights pursuant to Section 2.2.

     4.2. Expenses.  All expenses incurred by Rollins in connection with any
U.S. registration statement covering Registrable Securities offered by a Laidlaw
Party, including, without limitation, all registration and filing fees
(including all expenses incident to filing with the National Association of
Securities Dealers, Inc.), printing expenses, fees and disbursements of counsel
(except for the fees and disbursements of counsel for such Laidlaw Party) and of
the independent certified public accountants (except, in the case of any special
audits, if required in connection with any such registration, such Laidlaw
Party's proportionate share of its expense as provided in Section 2.3) and the
expense of qualifying such shares under state blue sky laws, shall be borne by
Rollins; provided, however, that Rollins shall not be required to pay for any
expenses of any registration proceeding begun pursuant to Section 2.2 if the
registration request is subsequently withdrawn at the request of a Laidlaw Party
(in which case such Laidlaw Party shall bear such expenses), unless the Laidlaw
Parties agree to forfeit their right to one demand registration pursuant to
Section 2.2; provided further, that if at the time of such withdrawal, such
Laidlaw Party has learned of a material adverse change in the condition,
business or prospects of Rollins from that known at the time of its request,
then such Laidlaw Party shall not be required to pay any of such expenses and
shall retain its rights pursuant to Section 2.2. Rollins's obligations under
this Section 4.2 shall apply to each registration under the Securities Act or
state blue sky legislation pursuant to Section 2.2.

     4.3. Offering Expenses.  The Laidlaw Party selling any Registrable
Securities pursuant to any prospectus filed with any Commission in connection
with the satisfaction by Rollins of its obligations under Section 2.2 shall
reimburse Rollins for all Offering Expenses reasonably incurred by or on behalf
of Rollins upon receipt by such Laidlaw Party of a written request from Rollins
in respect of same,



                                     A-B-11
<PAGE>


together with invoices outlining in reasonable detail the expenses to be borne
by the Laidlaw Party or Laidlaw Parties. In addition, the relevant Laidlaw
Parties shall be responsible for any additional expenses reasonably incurred by
Rollins as a result of such Laidlaw Parties' participation in any offering
proposed to be completed by Rollins in any Canadian jurisdiction as contemplated
in Section 2.1 upon receipt by the relevant Laidlaw Parties of a written request
from Rollins in respect of the same, together with appropriate documentation
outlining all expenses incurred by Rollins in respect of that distribution and
the proportion of the same to be borne by the relevant Laidlaw Parties, together
with a brief explanation as to the reasons why the expenses so charged to the
Laidlaw Parties would not have been incurred by Rollins in the absence of the
participation by the Laidlaw Parties in that distribution.

     4.4. Dispositions During Registration.  The Laidlaw Parties and their
Affiliates hereby agree that from the date of receipt of written notice (the
"Offering Notice") from Rollins that Rollins intends to file a registration
statement or prospectus (the "Offering Registration Statement") covering shares
of Common Stock or securities convertible into or exercisable for Common Stock
until the Offering Termination Date (defined below), the Laidlaw Parties and
their Affiliates will not sell or otherwise dispose of any securities owned by
such Laidlaw Party or Affiliate except for Registrable Shares included in the
Offering Registration Statement. As used herein, the "Offering Termination Date"
shall occur on (i) the lapse of 60 days from the date of receipt of the Offering
Notice if the Offering Registration Statement is not declared effective (or, if
the Offering Registration Statement is a (final) prospectus to be filed under
any Canadian Securities Act, a receipt is not issued therefor by the applicable
Commissions) before such lapse, (ii) the lapse of 120 days from the date of
effectiveness of the Offering Registration Statement (or, if the Offering
Registration Statement is a (final) prospectus to be filed under any Canadian
Securities Act, the date a receipt has been issued therefor by all applicable
Commissions) if any Registrable Shares are included in the Offering Registration
Statement or (iii) the lapse of 90 days from the date of effectiveness of the
Offering Registration Statement (or, if the Offering Registration Statement is a
(final) prospectus to be filed under any Canadian Securities Act, the date a
receipt has been issued therefor by all applicable Commissions) if no
Registrable Shares are included in the Offering Registration Statement.

     4.5. Transfer of Rights.  The incidental registration and qualification
rights or benefits and mandatory registration and qualification rights or
benefits, including indemnification by Rollins, shall be freely transferable by
the Laidlaw Parties (i) to any Laidlaw Affiliate and (ii) to any Person which
after such transfer would hold at least 10% of the issued and outstanding Common
Stock of Rollins. Upon any transfer of the registration and qualification rights
or benefits of this Registration Agreement, the assigning Laidlaw Party shall
give Rollins written notice prior to or promptly following such transfer stating
the name and address of the transferee and identifying the securities with
respect to which such rights are being assigned. Such notice shall include or be
accompanied by a written undertaking by the transferee to comply with the
obligations imposed hereunder. In the event any registration and qualification
rights or benefits are transferred in accordance with the terms hereof, any
actions required to be taken by the Laidlaw Parties will be taken with the
approval of the holders of such registration and qualification rights or
benefits who hold a majority of the Registrable Securities, whose actions shall
bind all such holders of such registration and qualification rights or benefits.

     4.6. Termination of Registration Rights.  The Laidlaw Parties and their
permitted assigns shall be entitled to exercise any right provided for in this
Registration Agreement until the twelfth anniversary of the date hereof,
provided, however, such rights shall terminate one year from the date 80% of the
Rollins Convertible Debenture has been converted or redeemed.

     4.7. Multijurisdictional Disclosure System.  Nothing in this Registration
Agreement shall be construed to limit or restrict in any manner whatsoever the
ability of Rollins to make use of the Multijurisdictional Disclosure System (as
set forth in National Policy No. 45 of the Canadian Securities Administrators)
with respect to the qualification, distribution or sale in Canada of any
securities of Rollins, including pursuant to request made pursuant to Section
2.1 or Section 2.2 hereof.



                                     A-B-12
<PAGE>


                                   ARTICLE V
                                 MISCELLANEOUS

     5.1. Notices.  All notices or other communications which are required or
may be given under this Registration Agreement shall be in writing and shall be
deemed to have been duly given when delivered in Person or transmitted by
telecopier (with receipt confirmed) to a party at the address or telecopy
number, as applicable, set forth below (as any such address or telecopier number
may be changed from time to time by notice similarly given):

          (i) if to any Laidlaw Party, to:

                 Laidlaw Inc.
                 3221 North Service Road
                 Burlington, Ontario
                 Canada L7R 3YS
                 Attention: Ivan R. Cairns
                 Telecopier No.: (905) 332-6550

          (ii) if to Rollins, to:

                 Rollins Environmental Services, Inc.
                 One Rollins Plaza
                 2200 Concord Pike
                 Wilmington, Delaware 19803
                 Attention: General Counsel
                 Telecopier No.: (302) 426-3555


     5.2. Section Headings.  The article and section headings in this
Registration Agreement are for reference purposes only and shall not affect the
meaning or interpretation of this Registration Agreement. References in this
Registration Agreement to a designated "Article" or "Section" refer to an
Article or Section of this Registration Agreement unless otherwise specifically
indicated.

     5.3. Governing Law.  This Registration Agreement shall be construed and
enforced in accordance with and governed by the laws of State of Delaware
without regard to its conflict of law rules.

     5.4. Amendments.  This Registration Agreement may be amended only by an
instrument in writing executed by all of the Parties.

     5.5. Entire Agreement.  This Registration Agreement constitutes the entire
agreement between the Parties concerning its subject matter.

     5.6. Severability.  The invalidity or unenforceability of any specific
provision of this Registration Agreement shall not invalidate or render
unenforceable any of its other provisions. Any provision of this Registration
Agreement held invalid or unenforceable shall be deemed reformed, if
practicable, to the extent necessary to render it valid and enforceable and to
the extent permitted by law and consistent with the intent of the Parties to
this Registration Agreement.

     5.7. Counterparts.  This Registration Agreement may be executed in multiple
counterparts, all of which together shall constitute the same instrument.



                                     A-B-13
<PAGE>


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

                                        ROLLINS ENVIRONMENTAL SERVICES, INC.

                                        By:
                                           ------------------------------------

                                        Name:
                                             ----------------------------------

                                        Title:
                                              ---------------------------------

                                        LAIDLAW INC.


                                        By:
                                           ------------------------------------

                                        Name:
                                             ----------------------------------

                                        Title:
                                              ---------------------------------

                                        LAIDLAW TRANSPORTATION, INC.


                                        By:
                                           ------------------------------------

                                        Name:
                                             ----------------------------------

                                        Title:
                                              ---------------------------------



                                     A-B-14


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