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                                                                     Exhibit 4.9


                           HMT TECHNOLOGY CORPORATION
                 5-3/4% CONVERTIBLE SUBORDINATED NOTES DUE 2004
                             REGISTRATION AGREEMENT
                                                              NEW YORK, NEW YORK

                             As of January 15, 1997


SALOMON BROTHERS INC
ALEX. BROWN & SONS INCORPORATED
HAMBRECHT & QUIST LLC
ROBERTSON, STEPHENS & COMPANY LLC
 c/o Salomon Brothers Inc
Seven World Trade Center
New York, New York 10048


Ladies and Gentlemen:

         HMT Technology Corporation., a Delaware corporation (the "Company"),
proposes to issue and sell (such issuance and sale, the "Initial Placement") to
you (the "Initial Purchasers"), upon the terms set forth in a purchase agreement
dated January 15, 1997 (the "Purchase Agreement"), $200,000,000 principal amount
(plus an additional $30,000,000 principal amount to cover over-allotments, if
any) of its 5-3/4% Convertible Subordinated Notes due 2004 (the "Securities").
The Securities will be convertible into shares of Common Stock, par value $0.001
per share (the "Common Stock"), of the Company at the conversion price set forth
in the Final Memorandum. As an inducement to you to enter into the Purchase
Agreement and in satisfaction of a condition to your obligations thereunder, the
Company agrees with you, (i) for your benefit and (ii) for the benefit of the
holders from time to time of the Securities or the Common Stock issuable upon
conversion of the Securities (including you) (each of the foregoing, a "Holder"
and together, the "Holders"), as follows:

         1. Definitions. Capitalized terms used herein without definition shall
have the respective meanings set forth in the Purchase Agreement. As used in
this Agreement, the following capitalized terms shall have the following
meanings:

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

                  "Affiliate" of any specified person means any other person
that, directly or indirectly, is in control of, is controlled by, or is under
common control with, such specified person. For purposes of this definition,
control of a person means the power, direct or indirect, to direct or cause the
direction of the management and policies of such person whether by contract or
otherwise; and the terms "controlling" and "controlled" have meanings
correlative to the foregoing.
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                  "Business Day" means any day that is neither a Saturday or a
Sunday nor a day on which banking institutions in The City of New York are
authorized or obligated by law or executive order to close.

                  "Closing Date" has the meaning set forth in the Purchase
Agreement.

                  "Commission" means the Securities and Exchange Commission.

                  "Damages Accrual Period" has the meaning set forth in Section
2(c) hereof.

                  "Damages Payment Date" has the meaning set forth in Section
2(c) hereof.

                  "Event" has the meaning set forth in Section 2(c) hereof.

                  "Event Date" has the meaning set forth in Section 2(c) hereof.

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

                  "Final Memorandum" has the meaning set forth in the Purchase
Agreement.

                  "Holder" has the meaning set forth in the preamble hereto.

                  "Indenture" means the Indenture relating to the Securities
dated as of January 15, 1997, between the Company and State Street Bank and
Trust Company, of California, N. A., as trustee, as the same may be amended from
time to time in accordance with the terms thereof.

                  "Initial Placement" has the meaning set forth in the preamble
hereto.

                  "Liquidated Damages" has the meaning set forth in Section 2(c)
hereof.

                  "Majority Holders" means the Holders of a majority of the then
outstanding aggregate principal amount of Securities registered under a Shelf
Registration Statement; provided, that Holders of Common Stock issued upon
conversion of Securities shall be deemed to be Holders of the aggregate
principal amount of Securities from which such Common Stock was converted.

                  "Managing Underwriters" means the Underwriter or Underwriters
that shall administer an Underwritten Offering.

                  "Notice Holder" has the meaning set forth in Section 2(b)
hereof.

                  "Prospectus" means the prospectus included in any Shelf
Registration Statement (including, without limitation, a prospectus that
discloses information previously omitted from a prospectus filed as part of an
effective registration statement in reliance upon Rule 430A under the Act), as
amended or supplemented by any prospectus supplement, with respect to the terms
of the


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offering of any portion of the Securities or Common Stock issuable upon
conversion thereof, covered by such Shelf Registration Statement, and all
amendments and supplements to such prospectus, including post-effective
amendments.

                  "Record Date" has the meaning set forth in Section 2(c)
hereof.

                  "Record Holder" has the meaning set forth in Section
2(c)hereof.

                  "Registrable Securities" shall mean the Securities and shares
of Common Stock issued upon conversion thereof, excluding any such securities
that, and any such securities the predecessors of which, were previously sold
pursuant to a registration statement of the Company filed under the Act or
pursuant to Rule 144 promulgated under the Act.

                  "Securities" has the meaning set forth in the preamble hereto.

                  "Selling Confirmation" means, with respect to a Notice Holder
and a Selling Notice given by such Notice Holder, a written notice given by the
Company to such Notice Holder instructing and notifying such Notice Holder that
the Shelf Registration Statement and Prospectus may be used during the
applicable Selling Period to effect the transactions described in such Selling
Notice, that the Company is then-currently in compliance with Section 3(b) and
that the Company reaffirms the consent granted pursuant to Section 3(f).

                  "Selling Notice" has the meaning set forth in Section 2(b)
hereof.

                  "Selling Period" means, with respect to a Notice Holder and a
Selling Notice given by such Notice Holder, a period of forty-five calendar days
commencing on the date such Notice Holder receives a Selling Confirmation in
respect of the transactions described in such Selling Notice; provided, that the
Company may defer existing Selling Periods in accordance with Section 3(c)(2).

                  "Shelf Registration" means a registration effected pursuant to
Section 2 hereof.

                  "Shelf Registration Period" has the meaning set forth in
Section 2(a) hereof.

                  "Shelf Registration Statement" means a "shelf" registration
statement of the Company pursuant to the provisions of Section 2 hereof
(including additional registration statements filed pursuant to Section 3(d))
which covers some or all of the Securities and the Common Stock issuable upon
conversion thereof, as applicable, on an appropriate form under Rule 415
promulgated under the Act, or any similar rule that may be adopted by the
Commission, and all amendments and supplements to such registration statement,
including post-effective amendments, in each case including the Prospectus
contained therein, all exhibits thereto and all material incorporated by
reference therein.

                  "Trustee" means the trustee with respect to the Securities
under the Indenture.


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                  "Underwriter" means any underwriter of Securities or Common
Stock issuable upon conversion thereof in connection with an offering thereof
under a Shelf Registration Statement.

                  "Underwritten Offering" means an offering in which the
Securities or Common Stock are sold to an Underwriter or with the assistance of
an Underwriter for reoffering to the public.

         2. Shelf Registration; Suspension of Use of Prospectus; Liquidated
Damages.

                  (a) The Company shall prepare and file with the Commission, as
soon as practicable but in any event on or prior to the date seventy-five (75)
days following the Closing Date, a Shelf Registration Statement under the Act
registering the resale from time to time by Holders thereof of all of the
Registrable Securities. The Shelf Registration Statement shall permit resales of
Registered Securities by Holders in the manner or manners designated by them
(including, without limitation, one or more Underwritten Offerings) from time to
time, which shall be set forth in such Shelf Registration Statement. The Company
shall use all reasonable efforts to cause the Shelf Registration Statement to be
declared effective under the Act as soon as practicable but in any event on or
prior to the date one hundred five (105) days following the Closing Date and to
keep the Shelf Registration Statement continuously effective under the Act until
the earlier of (i) the third anniversary of the last date of original issuance
of the Securities, (ii) the date on which the Securities or Common Stock
issuable upon conversion thereof may be sold by non-affiliates of the Company
pursuant to paragraph (k) of Rule 144 (or any successor provision) promulgated
by the Commission and (iii) such date as of which all the Securities or the
Common Stock issuable upon conversion thereof have been sold pursuant to the
Shelf Registration Statement (the period ending at such earlier date, the "Shelf
Registration Period").

                  (b) Each Holder of Registrable Securities agrees that if such
Holder wishes to sell its Registrable Securities pursuant to the Shelf
Registration Statement and the Prospectus, it will do so only in accordance with
this Section 2(b). Each Holder of Registrable Securities agrees to give written
notice to the Company at least four Business Days prior to any intended resale
of Registrable Securities under the Shelf Registration Statement, which notice
shall specify the date on which such Holder intends to begin such distribution
and such information with respect to such Holder and the intended distribution
as may be reasonably required to amend the Shelf Registration Statement or
supplement the Prospectus with respect to such intended distribution (each
Holder providing the notice described in this sentence and with respect to which
the related Selling Period is continuing or has been deferred, a "Notice
Holder"; each such notice, a "Selling Notice"). As soon as practicable after the
date a Selling Notice is received by the Company, and in any event within three
Business Days after such date, the Company shall either:

                           (i) (A) provide a Selling Confirmation to such Notice
Holder or (B) file a supplement to the Prospectus or a post-effective amendment
to the Shelf Registration Statement as required by Section 3(b), cause any such
amendment to become effective and immediately provide a Selling Confirmation to
such Notice Holder; or


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                           (ii) in the event of the happening of any event of
the kind described in Section 3(c)(2)(i), 3(c)(2)(ii), 3(c)(2)(iii) (y) or
3(c)(2)(iv) hereof, the Company shall deliver to such Notice Holder the notice
required by Section 3(c)(2) and notify the holder that the consent granted
pursuant to Section 3(f) is suspended until further notice.

                           Each such Notice Holder may sell all or any
Registrable Securities pursuant to the Shelf Registration Statement and the
Prospectus only during the Selling Period commencing with the earlier of (x) the
date on which such Notice Holder receives a Selling Confirmation and (y) the
fourth Business Day after the related Selling Notice has been received by the
Company; provided that in the event the Company elects to take the actions
permitted by Section 2(b)(ii), the commencement of the Selling Period shall be
deferred until such later date as the Company delivers a Selling Confirmation. A
Notice Holder shall not sell any Registrable Securities pursuant to the Shelf
Registration Statement or the Prospectus after the expiration of the applicable
Selling Period without giving a new Selling Notice pursuant to Section 2(b)
hereof and receiving new Selling Confirmation. Notwithstanding the foregoing,
the Company shall not under any circumstances be entitled to exercise its right
under this paragraph to defer the commencement of a Selling Period or its right
under Section 3(c)(2) to defer existing Selling Periods, in the aggregate, more
than one time in any three month period or three times in any twelve month
period, and the period in which a Selling Period is deferred shall not exceed
thirty (30) days. In no event shall the Company be permitted to extend the
period during which the commencement of any such Selling Period is deferred
(whether pursuant to this paragraph or Section 3(c)(2) from and after the date a
Notice Holder provides a Selling Notice to the Company in accordance with this
Section 2(c) (a "Deferral Period") beyond such thirty (30) day period.

                  In the event the Company elects to take the actions described
in Section 2(b)(ii), the Company will, at such time as it is in compliance with
Section 3(b) and as use of the Prospectus may be resumed, immediately provide
Selling Confirmations to all Notice Holders.

                  (c) The parties hereto agree that the Holders of the
Registrable Securities will suffer damages, and that it would not be feasible to
ascertain the extent of such damages with precision, if (i) the Shelf
Registration statement has not been filed on or prior to the date seventy-five
(75) days following the Closing Date, (ii) the Shelf Registration Statement has
not been declared effective under the Securities Act on or before the date one
hundred five (105) days following the Closing Date, (iii) prior to the end of
the Shelf Registration Period, the Commission shall have issued a stop order
suspending the effectiveness of the Shelf Registration Statement or proceedings
have been initiated with respect to the Shelf Registration Statement under
Section 8(d) or 8(e) of the Act, (iv) the aggregate number of days in any one
Deferral Period exceeds the periods permitted pursuant to Section 2(b) hereof or
(v) the number of Deferral Periods exceeds the number permitted pursuant to
Section 2(b) hereof (each of the events of a type described in any of the
foregoing clauses (i) through (v) are individually referred to herein as an
"Event"; and the date seventy-five (75) days following the Closing Date in the
case of clause (i), the date one hundred five days following the Closing Date in
the case of clause (ii), the date on which the effectiveness of the Shelf
Registration Statement has been suspended or proceedings with respect to the
Shelf Registration Statement under Section 8(d) or 8(e) of the Act have been
commenced in the case of clause (iii), the date on which the


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duration of a Deferral Period exceeds the periods permitted by Section 2(c)
hereof in the case of clause (iv), and the date of the commencement of a
Deferral Period that causes the limit on the number of Deferral Periods under
Section 2(b) hereof to be exceeded in the case of clause (v), are referred to
herein as an "Event Date"). Events shall be deemed to continue until the date of
the termination of such Event, which shall be the following date with respect to
the respective types of Events: the date the Registration Statement is filed in
the case of an Event of the type described in clause (i), the date the
Registration Statement is declared effective under the Act in the case of an
Event described in clause (ii), the date that all stop orders suspending
effectiveness of the Shelf Registration Statement have been removed and the
proceedings initiated with respect to the Shelf Registration Statement under
Section 8(d) or 8(e) of the Act have terminated, as the case may be, in the case
of Events of the types described in clause (iii), termination of the Deferral
Period which caused the aggregate number of days in any one Deferral Period to
exceed the number permitted by Section 2(b) to be exceeded in the case of Events
of the type described in clause (iv), and termination of the Deferral Period the
commencement of which caused the number of Deferral Periods permitted by Section
2(b)(ii) to be exceeded in the case of Events of the type described in clause
(v).

                  Accordingly, upon the occurrence of any Event and until such
time as there are no Events which have occurred and are continuing (a "Damages
Accrual Period"), commencing on the Event Date on which such Damages Accrual
Period began, the Company agrees to pay, as liquidated damages, and not as a
penalty, an additional amount (the "Liquidated Damages"): (A) to each Holder of
Registrable Securities that is a Notice Holder, accruing at a rate equal to
one-half of one percent per annum (50 basis points) on (s) where such
Registrable Securities are Securities, the aggregate principal amount of such
Securities held by such Notice Holder and (t) where such Registrable Securities
are shares of Common Stock issued upon conversion of Securities, the aggregate
principal amount of Securities that were converted into such shares and (B) if
the Damages Accrual Period continues for a period in excess of thirty days from
the Event Date, from and after the end of such thirty day period until such time
as there are no Events which have occurred and are continuing, to each Holder of
Registrable Securities (whether or not a Notice Holder), accruing at a rate
equal to one-half of one percent per annum (50 basis points) on (u) where such
Registrable Securities are Securities, the aggregate principal amount of such
Securities held by such Holder and (v) where such Registrable Securities are
shares of Common Stock issued upon conversion of Securities, the aggregate
principal amount of Securities that were converted into such shares.
Notwithstanding the foregoing, no Liquidated Damages shall accrue under clause
(A) of the preceding sentence during any period for which Liquidated Damages
accrue under clause (B) of the preceding sentence or as to any Securities or
shares of Common Stock from and after the earlier of (x) the date such
securities are no longer Registrable Securities, and (y) the expiration of the
Shelf Registration Period. In addition, Liquidated Damages will not accrue as to
any Securities or Common Stock issuable upon the conversion thereof represented
by the Unrestricted Global Note (as defined in the Indenture) provided that such
securities are not subject to limitations on transfer under United States
federal or state securities laws and there shall have been at least six months
during which the Shelf Registration Statement was effective and the Prospectus
included therein was available for effecting resales of the Securities and the
Common Stock issuable upon conversion thereof. The rate of accrual of the
Liquidated Damages with respect to any period shall not exceed the rate provided
for in this paragraph notwithstanding the occurrence of multiple concurrent
Events.


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                  Liquidated Damages due on any Securities or Common Stock shall
be payable on each Interest Payment Date on the Securities occurring (or if
there are no Securities outstanding, which would have occurred) during the
Damages Accrual Period and on the Interest Payment Date immediately following
(or which would have followed) the termination of such Period (a "Damages
Payment Date"). The Company shall pay the Liquidated Damages due on any
Securities by depositing with the Trustee under the Indenture, in trust, for the
benefit of the Holders of Securities or Common Stock or Notice Holders, as the
case may be, entitled thereto, at least one Business Day prior to the applicable
Damages Payment Date, sums sufficient to pay the Liquidated Damages accrued or
accruing since the last preceding Damages Payment Date to such Damages Payment
Date. The Liquidated Damages shall be paid on each Damages Payment Date to the
Holders of record of the Registrable Securities (the "Record Holders") on the
15th day of January or 15th day of July (each a "Record Date") immediately
preceding such Damages Payment Date by wire transfer of immediately available
funds to the accounts specified by them or by mailing checks to their registered
addresses as they appear in the Securities register or stock transfer books of
the Company, if no such accounts have been specified on or before the
applicable Regular Record Date. The Trustee shall be entitled, on behalf of the
Holders of Securities, Common Stock and Notice Holders, to seek any available
remedy for the enforcement of this Agreement, including for the payment of such
Liquidated Damages.

                  Notwithstanding the foregoing, the parties agree that the sole
remedy payable for a violation of the terms of this Agreement with respect to
which Liquidated Damages are expressly provided shall be such Liquidated
Damages. Nothing shall preclude a Notice Holder or Holder of Registrable
Securities from pursuing or obtaining specific performance or other equitable
relief with respect to any violation of this Agreement for which liquidated
damages are not expressly provided by this Agreement.

                  All of the Company's obligations set forth in this Section
2(c) which are outstanding with respect to any Registrable Securities at the
time such security ceases to be a Registrable Security shall survive until such
time as all such obligations with respect to such security have been satisfied
in full (notwithstanding termination of the Agreement).

                  The parties hereto agree that the Liquidated Damages provided
for in this Section 2(c) constitute a reasonable estimate of the damages that
may be incurred by Holders of Registrable Securities (other than the Initial
Purchasers) by reason of the failure of the Shelf Registration Statement to be
filed or declared effective or unavailable (absolutely or as a practical matter)
for effecting resales of Registrable Securities, as the case may be, in
accordance with the provisions hereof.

         3. Registration Procedures. In connection with any Shelf Registration
Statement, the following provisions shall apply:

                  (a) The Company shall furnish to you, prior to the filing
thereof with the Commission, a copy of any Shelf Registration Statement, and
each amendment thereof and each amendment or supplement, if any, to the
Prospectus included therein and shall use its best efforts to


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reflect in each such document, when so filed with the Commission, such comments
as Salomon Brothers Inc reasonably may propose.

                  (b) The Company shall ensure that (i) any Shelf Registration
Statement and any amendment thereto and any Prospectus forming part thereof and
any amendment or supplement thereto comply in all material respects with the Act
and the rules and regulations thereunder, (ii) any Shelf Registration Statement
and any amendment thereto does not, when it becomes effective, contain an 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
(iii) any Prospectus forming part of any Shelf Registration Statement, and any
amendment or supplement to such Prospectus, does not include an untrue statement
of a material fact or omit to state a material fact necessary in order to make
the statements therein, in light of the circumstances under which they were
made, not misleading; provided that no representation or agreement is made
hereby with respect to information with respect to you or any Holder required to
be included in any Shelf Registration or Prospectus pursuant to the Act or the
rules and regulations thereunder or provided by you, any Holder, or any Managing
Underwriter specifically for inclusion in any Shelf Registration Statement or
Prospectus.

                  (c) (1) The Company shall advise you and the Holders and, if
requested by you or any such Holder, confirm such advice in writing:

                  (i) when a Shelf Registration Statement and any amendment
         thereto has been filed with the Commission and when the Shelf
         Registration Statement or any post-effective amendment thereto has
         become effective; and

                  (ii) of any request by the Commission for amendments or
         supplements to the Shelf Registration Statement or the Prospectus
         included therein or for additional information.

                  (2) During any Selling Period, during the deferral of any
Selling Period and within three Business Days of receipt by the Company of any
Selling Notice, the Company shall notify you and the Notice Holders and, if
requested by you or any such Notice Holder, confirm such notification in
writing:

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

                  (ii) of the receipt by the Company of any notification with
         respect to the suspension of the qualification of the Securities
         included in any Shelf Registration Statement for sale in any
         jurisdiction or the initiation or threat of any proceeding for such
         purpose;

                  (iii) of (x) the suspension of the use of the Prospectus
         pursuant to Section 2(b) hereof or (y) of the happening of any event
         that requires the making of any changes in the Shelf Registration
         Statement or the Prospectus so that, as of such date, the statements
         therein are not misleading and do not omit to state a material fact
         required to be stated therein or


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         necessary to make the statements therein (in the case of the
         Prospectus, in light of the circumstances under which they were made)
         not misleading; and

                  (iv) of the determination by the Company, in its judgment,
         that it is advisable to suspend use of the Prospectus for valid
         business reasons (not including avoidance of the Company's obligations
         hereunder) including, among other things, the acquisition or
         divestiture of assets, public filings with the Commission, pending
         corporate developments and similar events;

which notice shall be accompanied by an instruction to defer the use of the
Prospectus until the Company delivers a Selling Confirmation whereupon any
existing Selling Period shall be deferred and shall recommence upon delivery of
the aforementioned Selling Confirmation; provided, that such Selling Period
shall be extended by the number of days elapsed in such period prior to such
deferral.

                  (d) The Company shall use its best efforts to obtain the
withdrawal of any order suspending the effectiveness of any Shelf Registration
Statement at the earliest possible time, and in any event shall within thirty
(30) days of any such order amend the Shelf Registration Statement in a manner
reasonably expected to obtain the withdrawal of such order, or file an
additional Shelf Registration Statement covering all of the Registrable
Securities (whereupon references herein to the Shelf Registration Statement
shall be deemed to include reference to such additional filing).

                  (e) The Company shall furnish to each Holder of Securities or
the Common Stock issued upon conversion thereof included within the coverage of
any Shelf Registration Statement, without charge, at least one copy of such
Shelf Registration Statement and any post-effective amendment thereto, including
financial statements and schedules, and, if the Holder so requests in writing,
all exhibits (including those incorporated by reference).

                  (f) The Company shall, during the Shelf Registration Period,
deliver to each Holder of Securities or the Common Stock issued upon conversion
thereof included within the coverage of any Shelf Registration Statement,
without charge, as many copies of the Prospectus (including each preliminary
Prospectus) included in such Shelf Registration Statement and any amendment or
supplement thereto as such Holder may reasonably request; and, except during
such periods as the Company shall have suspended the use of the Prospectus
pursuant to Section 2(b) or 3(c)(2), the Company consents to the use of the
Prospectus or any amendment or supplement thereto by each of the selling Holders
in connection with the offering and sale of the Securities or the Common Stock
issued upon conversion thereof covered by the Prospectus or any amendment or
supplement thereto.

                  (g) Prior to any offering of Securities or the Common Stock
issued upon conversion thereof pursuant to any Shelf Registration Statement, the
Company shall register or qualify or cooperate with the Holders of Securities or
the Common Stock issued upon conversion thereof included therein and their
respective counsel in connection with the registration or qualification of such
Securities or Common Stock for offer and sale under the securities or blue sky
laws of such jurisdictions as any such Holders reasonably request in writing and
do any and all other


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acts or things necessary or advisable to enable the offer and sale in such
jurisdictions of the Securities and the Common Stock issued upon conversion
thereof covered by such Shelf Registration Statement; provided, however, that
the Company will not be required to qualify generally to do business in any
jurisdiction where it is not then so qualified or to take any action which would
subject it to general service of process or to taxation in any such jurisdiction
where it is not then so subject.

                  (h) The Company shall cooperate with the Holders to facilitate
the timely preparation and delivery of certificates representing Securities or
the Common Stock issued upon conversion thereof to be sold pursuant to any Shelf
Registration Statement free of any restrictive legends and in such denominations
and registered in such names as Holders may request prior to sales of Securities
or the Common Stock issued upon conversion thereof pursuant to such Shelf
Registration Statement.

                  (i) Upon the occurrence of any event contemplated by paragraph
(c)(2)(iii) above, the Company shall promptly prepare a post-effective amendment
to any Shelf Registration Statement or an amendment or supplement to the related
Prospectus or file any other required document so that, as thereafter delivered
(when and as permitted pursuant to Section 2(c)) to purchasers of the Securities
or the Common Stock issued upon conversion thereof included therein, the
Prospectus will not include an untrue statement of a material fact or omit to
state any material fact necessary to make the statements therein, in the light
of the circumstances under which they were made, not misleading.

                  (j) The Company shall use its best efforts to cause The
Depository Trust Company ("DTC") on the first Business Day following the
effective date of any Shelf Registration Statement hereunder or as soon as
possible thereafter to remove (i) from any existing CUSIP number assigned to the
Securities any designation indicating that the Securities are "restricted
securities", which efforts shall include delivery to DTC of a letter executed by
the Company substantially in the form of Exhibit A hereto and (ii) any other
stop or restriction on DTC's system with respect to the Securities. In the event
the Company is unable to cause DTC to take the actions described in the
immediately preceding sentence, the Company shall take such actions as Salomon
Brothers Inc may reasonably request to provide, as soon as practicable, a CUSIP
number for the Securities registered under such Shelf Registration Statement and
to cause such CUSIP number to be assigned to the Securities (or to the maximum
aggregate principal amount of the Securities to which such number may be
assigned). Upon compliance with the foregoing requirements of this Section 3(j),
the Company shall provide the Trustee with printed certificates for such
Securities, in a form eligible for deposit with DTC.

                  (k) The Company shall use its best efforts to comply with all
applicable rules and regulations of the Commission and shall make generally
available to its security holders as soon as practicable after the effective
date of the applicable Shelf Registration Statement an earnings statement
satisfying the provisions of Section 11(a) of the Act and Rule 158 promulgated
by the Commission thereunder.

                  (l) The Company shall cause the Indenture to be qualified
under the Trust Indenture Act in a timely manner.


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                  (m) The Company may require each Holder of Securities or the
Common Stock issued upon conversion thereof to be sold pursuant to any Shelf
Registration Statement to furnish to the Company such information regarding the
Holder and the distribution of such Securities or Common Stock as may, from time
to time, be required by the Act and the rules and regulations promulgated
thereunder, and the obligations of the Company to any Holder hereunder shall be
expressly conditioned on the compliance of such Holder with such request.

                  (n) The Company shall, if requested, use its best efforts to
promptly incorporate in a Prospectus supplement or post-effective amendment to a
Shelf Registration Statement (i) such information as the Majority Holders or, if
the Securities or Common Stock are being sold in an Underwritten Offering, as
the Managing Underwriters and the Majority Holders reasonably agree should be
included therein and provide to the Company in writing for inclusion in the
Shelf Registration Statement or Prospectus, and (ii) such information as a
Holder may provide from time to time to the Company in writing for inclusion in
a Prospectus or any Shelf Registration Statement concerning such Holder and the
distribution of such Holder's Securities and Common Stock and, in either case,
shall make all required filings of such Prospectus supplement or post-effective
amendment as soon as notified of the matters to be incorporated in such
Prospectus supplement or post-effective amendment.

                  (o) The Company shall enter into such agreements (including
underwriting agreements) and take all other appropriate actions in order to
expedite or facilitate the registration or the disposition of the Securities or
the Common Stock issuable upon conversion thereof, and in connection therewith,
if an underwriting agreement is entered into, cause the same to contain
indemnification provisions and procedures no less favorable to the Holders than
those set forth in Section 5 (or such other provisions and procedures acceptable
to the Majority Holders and the Managing Underwriters, if any, with respect to
all parties to be indemnified pursuant to Section 5 from Holders of Securities
or the Common Stock issuable upon conversion thereof to the Company).

                  (p) The Company shall (i) make reasonably available for
inspection by the Holders of Securities or the Common Stock issued upon
conversion thereof to be registered under a Shelf Registration Statement, any
Underwriter participating in any disposition pursuant to such Shelf Registration
Statement, and any attorney, accountant or other agent retained by the Holders
or any such Underwriter all relevant financial and other records, pertinent
corporate documents and properties of the Company and its subsidiaries; (ii)
cause the Company's officers, directors and employees to supply all relevant
information reasonably requested by the Holders or any such Underwriter,
attorney, accountant or agent in connection with any such Shelf Registration
Statement as is customary for similar due diligence examinations; provided,
however, that any information that is designated in writing by the Company, in
its sole discretion, as confidential at the time of delivery of such information
shall be kept confidential by the Holders or any such Underwriter, attorney,
accountant or agent, unless disclosure thereof is made in connection with a
court proceeding or required by law, or such information has become available to
the public generally or through a third party without an accompanying obligation
of confidentiality; (iii) make such representations and warranties to the
Holders of Securities or the Common Stock issued upon conversion thereof
registered thereunder and the Underwriters, if any, in form, substance and scope
as are customarily


                                      -11-
   12
made by issuers to Underwriters and covering matters including, but not limited
to, those set forth in the Purchase Agreement; (iv) obtain opinions of counsel
to the Company and updates thereof (which counsel and opinions, in form, scope
and substance, shall be reasonably satisfactory to the Managing Underwriters, if
any) addressed to each selling Holder and the Underwriters, if any, covering
such matters as are customarily covered in opinions requested in underwritten
offerings and such other matters as may be reasonably requested by such Holders
and Underwriters; (v) obtain "cold comfort" letters and updates thereof from the
independent certified public accountants of the Company (and, if necessary, any
other independent certified public accountants of any subsidiary of the Company
or of any business acquired by the Company for which financial statements and
financial data are, or are required to be, included in the Shelf Registration
Statement), addressed to each selling Holder of Securities or the Common Stock
issued upon conversion thereof registered thereunder (provided such Holder
furnishes the accountants with such representations as the accountants
customarily require in similar situations) and the Underwriters, if any, in
customary form and covering matters of the type customarily covered in "cold
comfort" letters in connection with primary underwritten offerings; and (vi)
deliver such documents and certificates as may be reasonably requested by the
Majority Holders and the Managing Underwriters, if any, including those to
evidence compliance with Section 3(i) and with any customary conditions
contained in the underwriting agreement or other agreement entered into by the
Company. The foregoing actions set forth in clauses (iii), (iv), (v) and (vi) of
this Section 3(p) shall be performed at (A) the effectiveness of such Shelf
Registration Statement and each post-effective amendment thereto and (B) each
closing under any underwriting or similar agreement as and to the extent
required thereunder.

         4. Registration Expenses. The Company shall bear all expenses incurred
in connection with the performance of its obligations under Sections 2 and 3
hereof and shall reimburse the Holders for the reasonable fees and disbursements
of one firm or counsel designated by the Majority Holders to act as counsel for
the Holders in connection therewith.

         5. Indemnification and Contribution.

                  (a) (i) In connection with any Shelf Registration Statement,
the Company agrees to indemnify and hold harmless each Holder of Securities or
Common Stock issued upon conversion thereof covered thereby (including the
Initial Purchasers), the directors, officers, employees and agents of each such
Holder and each person who controls any such Holder within the meaning of either
the Act or the Exchange Act against any and all losses, claims, damages or
liabilities, joint or several, to which they or any of them may become subject
under the Act, the Exchange Act or other Federal or state statutory law or
regulation, at common law or otherwise, insofar as such losses, claims, damages
or liabilities (or actions in respect thereof) arise out of or are based upon
any untrue statement or alleged untrue statement of a material fact contained in
the Shelf Registration Statement as originally filed or in any amendment
thereof, or in any preliminary Prospectus or Prospectus, or in any amendment
thereof or supplement thereto, or arise out of or are based upon the omission or
alleged omission to state therein a material fact required to be stated therein
or necessary to make the statements therein not misleading, and agrees to
reimburse each such indemnified party, as incurred, for any legal or other
expenses reasonably incurred by them in connection with investigating or
defending any such loss, claim, damage, liability or action; provided,


                                      -12-
   13
however, that the Company will not be liable in any case to the extent that any
such loss, claim, damage or liability arises out of or is based upon (A) any
such untrue statement or alleged untrue statement or omission or alleged
omission made therein in reliance upon and in conformity with written
information furnished to the Company by or on behalf of any such Holder or any
Initial Purchaser specifically for inclusion therein, (B) use of a Shelf
Registration Statement or the related Prospectus during a period when a stop
order has been issued in respect of such Shelf Registration or any proceedings
for that purpose have been initiated or use of a Prospectus when use of such
Prospectus has been deferred pursuant to Section 2(c); provided, further, in
each case, that the Company delivered prior notice, and the Holders have
received such prior notice, in accordance with Section 6(c) hereof of such stop
order, initiation of proceedings or deferral or (C) if the Holder fails to
deliver a Prospectus or the then current Prospectus. This indemnity agreement
will be in addition to any liability which the Company may otherwise have.

                           (ii) The Company also agrees to indemnify or
contribute to Losses, as provided in Section 5(d), of any Underwriters of
Securities or the Common Stock issued upon conversion thereof registered under a
Shelf Registration Statement, their officers and directors and each person who
controls such Underwriters on substantially the same basis as that of the
indemnification of the Initial Purchasers and the selling Holders provided in
this Section 5(a) and shall, if requested by any Holder, enter into an
underwriting agreement reflecting such agreement, as provided in Section 3(o)
hereof.

                  (b) Each Holder of Securities or Common Stock issued upon
conversion thereof covered by a Shelf Registration Statement (including the
Initial Purchasers) severally agrees to indemnify and hold harmless (i) the
Company, (ii) each of its directors, (iii) each of its officers who signs such
Shelf Registration Statement and (iv) each person who controls the Company
within the meaning of either the Act or the Exchange Act to the same extent as
the foregoing indemnity from the Company to each such Holder, but only with
reference to written information relating to such Holder furnished to the
Company by or on behalf of such Holder specifically for inclusion in the
documents referred to in the foregoing indemnity. This indemnity agreement will
be in addition to any liability which any such Holder may otherwise have.

                  (c) Promptly after receipt by an indemnified party under this
Section 5 of notice of the commencement of any action, such indemnified party
will, if a claim in respect thereof is to be made against the indemnifying party
under this Section 5, notify the indemnifying party in writing of the
commencement thereof; but the failure so to notify the indemnifying party (i)
will not relieve it from liability under paragraph (a) or (b) above unless and
to the extent it did not otherwise learn of such action and such failure results
in the forfeiture by the indemnifying party of substantial rights and defenses
and (ii) will not, in any event, relieve the indemnifying party from any
obligations to any indemnified party other than the indemnification obligation
provided in paragraph (a) or (b) above. The indemnifying party shall be entitled
to appoint counsel of the indemnifying party's choice at the indemnifying
party's expense to represent the indemnified party in any action for which
indemnification is sought (in which case the indemnifying party shall not
thereafter be responsible for the fees and expenses of any separate counsel
retained by the indemnified party or parties except as set forth below);
provided, however, that such counsel shall be satisfactory to the indemnified
party.


                                      -13-
   14
Notwithstanding the indemnifying party's election to appoint counsel to
represent the indemnified party in an action, the indemnified party shall have
the right to employ separate counsel (including local counsel), and the
indemnifying party shall bear the reasonable fees, costs and expenses of such
separate counsel (and local counsel) if (i) the use of counsel chosen by the
indemnifying party to represent the indemnified party would present such counsel
with a conflict of interest, (ii) the actual or potential defendants in, or
targets of, any such action include both the indemnified party and the
indemnifying party and the indemnified party shall have reasonably concluded
that there may be legal defenses available to it and/or other indemnified
parties which are different from or additional to those available to the
indemnifying party, (iii) the indemnifying party shall not have employed counsel
satisfactory to the indemnified party to represent the indemnified party within
a reasonable time after notice of the institution of such action or (iv) the
indemnifying party shall authorize the indemnified party to employ separate
counsel at the expense of the indemnifying party; provided further, that the
indemnifying party shall not be responsible for the fees and expenses of more
than one separate counsel (together with appropriate local counsel) representing
all the indemnified parties under paragraph (a)(i), paragraph (a)(ii) or
paragraph (b) above. An indemnifying party will not, without the prior written
consent of the indemnified parties, settle or compromise or consent to the entry
of any judgment with respect to any pending or threatened claim, action, suit or
proceeding in respect of which indemnification or contribution may be sought
hereunder (whether or not the indemnified parties are actual or potential
parties to such claim or action) unless such settlement, compromise or consent
includes an unconditional release of each indemnified party from all liability
arising out of such claim, action, suit or proceeding.

                  (d) In the event that the indemnity provided in paragraph (a)
or (b) of this Section 5 is unavailable to or insufficient to hold harmless an
indemnified party for any reason, then each applicable indemnifying party, in
lieu of indemnifying such indemnified party, shall have a joint and several
obligation to contribute to the aggregate losses, claims, damages and
liabilities (including legal or other expenses reasonably incurred in connection
with investigating or defending same) (collectively "Losses") to which such
indemnified party may be subject in such proportion as is appropriate to reflect
the relative benefits received by such indemnifying party, on the one hand, and
such indemnified party, on the other hand, from the Initial Placement and the
Shelf Registration Statement which resulted in such Losses; provided, however,
that in no case shall the Initial Purchasers be responsible, in the aggregate,
for any amount in excess of the purchase discount or commission applicable to
such Security, as set forth on the cover page of the Final Memorandum (unless
such Initial Purchaser shall also be an Underwriter, in which case, such Initial
Purchaser shall also be responsible for amounts pursuant to the remaining of
this sentence), nor shall any Underwriter be responsible for any amount in
excess of the underwriting discount or commission applicable to the Securities
and Common Stock issued upon conversion thereof purchased by such Underwriter
under the Shelf Registration Statement which resulted in such Losses. If the
allocation provided by the immediately preceding sentence is unavailable for any
reason, the indemnifying party and the indemnified party shall contribute in
such proportion as is appropriate to reflect not only such relative benefits but
also the relative fault of such indemnifying party, on the one hand, and such
indemnified party, on the other hand, in connection with the statements or
omissions which resulted in such Losses as well as any other relevant equitable
considerations. Benefits received by the Company shall be deemed to be equal to
the sum of (x) the total net proceeds from the Initial Placement (before
deducting


                                      -14-
   15
expenses) as set forth on the cover page of the Final Memorandum and (y) the
total amount of additional interest which the Company was not required to pay as
a result of registering the Securities and Common Stock issued upon conversion
thereof covered by the Shelf Registration Statement which resulted in such
Losses. Benefits received by the Initial Purchasers shall be deemed to be equal
to the total purchase discounts and commissions as set forth on the cover page
of the Final Memorandum, and benefits received by any other Holders shall be
deemed to be equal to the value of receiving Securities or the Common Stock
issuable upon conversion thereof registered under the Act. Benefits received by
any Underwriter shall be deemed to be equal to the total underwriting discounts
and commissions, as set forth on the cover page of the Prospectus forming a part
of the Shelf Registration Statement which resulted in such Losses. Relative
fault shall be determined by reference to whether any alleged untrue statement
or omission relates to information provided by the indemnifying party, on the
one hand, or by the indemnified party, on the other hand. The parties agree that
it would not be just and equitable if contribution were determined by pro rata
allocation or any other method of allocation which does not take account of the
equitable considerations referred to above. Notwithstanding the provisions of
this paragraph (d), no person guilty of fraudulent misrepresentation (within the
meaning of Section 11(f) of the Act) shall be entitled to contribution from any
person who was not guilty of such fraudulent misrepresentation. For purposes of
this Section 5, each person who controls a Holder within the meaning of either
the Act or the Exchange Act and each director, officer, employee and agent of
such Holder shall have the same rights to contribution as such Holder, and each
person who controls the Company within the meaning of either the Act or the
Exchange Act, each officer of the Company who shall have signed the Shelf
Registration Statement and each director of the Company shall have the same
rights to contribution as the Company, subject in each case to the applicable
terms and conditions of this paragraph (d).

                  (e) The provisions of this Section 5 will remain in full force
and effect, regardless of any investigation made by or on behalf of any Holder
or the Company or any of the officers, directors or controlling persons referred
to in Section 5 hereof, and will survive the sale by a Holder of Securities
covered by a Shelf Registration Statement.

         6.       Miscellaneous.

                  (a) No Inconsistent Agreements. The Company has not, as of the
date hereof, entered into nor shall it, on or after the date hereof, enter into,
any agreement with respect to its Securities that is inconsistent with the
rights granted to the Holders herein or otherwise conflicts with the provisions
hereof.

                  (b) Amendments and waivers. The provisions of this Agreement,
including the provisions of this sentence, may not be amended, qualified,
modified or supplemented, and waivers or consents to departures from the
provisions hereof may not be given, unless the Company has obtained the written
consent of the Majority Holders; provided that, with respect to any matter that
directly or indirectly affects the rights of the Initial Purchasers hereunder,
the Company shall obtain the written consent of the Initial Purchasers against
which such amendment, qualification, supplement, waiver or consent is to be
effective. Notwithstanding the foregoing (except the foregoing proviso), a
waiver or consent to departure from the provisions hereof with respect to a
matter that relates exclusively to the


                                      -15-
   16
rights of Holders whose Securities are being sold pursuant to a Shelf
Registration Statement and that does not directly or indirectly affect the
rights of other Holders may be given by the Majority Holders, determined on the
basis of Securities being sold rather than registered under such Shelf
Registration Statement.

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

                           (i) if to you, initially at the address set forth in
         the Purchase Agreement;

                           (ii) if to any other Holder, at the most current
         address given by such Holder to the Company in accordance with the
         provisions of this Section 6(c), which address initially is, with
         respect to each Holder, the address of such Holder maintained by the
         Registrar under the Indenture, with a copy in like manner to Salomon
         Brothers Inc; and

                           (iii) if to the Company, initially at its address set
         forth in the Purchase Agreement.

                  All such notices and communications shall be deemed to have
been duly given when received, if delivered by hand or air courier, and when
sent, if sent by first-class mail, telex or telecopier.

                  The Initial Purchasers or the Company by notice to the other
may designate additional or different addresses for subsequent notices or
communications.

                  (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 the need for an express assignment or any consent by
the Company thereto, subsequent Holders. The Company hereby agrees to extend the
benefits of this Agreement to any Holder and any such Holder may specifically
enforce the provisions of this Agreement as if an original party hereto.

                  (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 applicable to
agreements made and to be performed in said State, without regard to the
conflicts of law rules thereof.


                                      -16-
   17
                  (h) Severability. In the event that any one of more of the
provisions contained herein, or the application thereof in any circumstances, is
held invalid, illegal or unenforceable in any respect for any reason, the
validity, legality and enforceability of any such provision in every other
respect and of the remaining provisions hereof shall not be in any way impaired
or affected thereby, it being intended that all of the rights and privileges of
the parties shall be enforceable to the fullest extent permitted by law.

                  (i) Securities Held by the Company, etc. Whenever the consent
or approval of Holders of a specified percentage of principal amount of
Securities or the Common Stock issuable upon conversion thereof is required
hereunder, Securities or the Common Stock issued upon conversion thereof held by
the Company or its Affiliates (other than subsequent Holders of Securities or
the Common Stock issued upon conversion thereof if such subsequent Holders are
deemed to be Affiliates solely by reason of their holdings of such Securities)
shall not be counted in determining whether such consent or approval was given
by the Holders of such required percentage.

         Please confirm that the foregoing correctly sets forth the agreement
between the Company and you.


                                      Very truly yours,

                                      HMT TECHNOLOGY CORPORATION

                                       /s/ Peter S. Norris
                                      --------------------------------------
                                      Name: Peter S. Norris     
                                      Title: Chief Financial Officer

The foregoing Agreement is hereby
confirmed and accepted as of the
date first above written.


SALOMON BROTHERS INC
ALEX. BROWN & SONS INCORPORATED
HAMBRECHT & QUIST LLC
ROBERTSON, STEPHENS & COMPANY LLC
By: Salomon Brothers Inc

 /s/ Richard J. Gallivan
- ------------------------------------
Name: Richard J. Gallivan
Title: Vice President


                                      -17-
   18
                                                                       EXHIBIT A

                   FORM OF LETTER TO BE PROVIDED BY ISSUER TO
                          THE DEPOSITORY TRUST COMPANY



The Depository Trust Company
7 Hanover Square, 23rd Floor
New York, NY  10004

       Re: 5-3/4% Convertible Subordinated Notes due 2004 (the "Securities") of
           HMT Technology Corporation (the "Issuer")

Ladies and Gentlemen:

         Please be advised that the Securities and Exchange Commission has
declared effective a Registration Statement on Form S-3 under the Securities Act
of 1933, as amended, with regard to all of the Securities referenced above.
Accordingly, there is no longer any restriction as to whom such Securities may
be sold and any restrictions on the CUSIP designation are no longer appropriate
and may be removed. I understand that upon receipt of this letter, DTC will
remove any stop or restriction on its system with respect to this issue.

         As always, please do not hesitate to call if we can be of further
assistance.


                                        Very truly yours,



                                        Authorized Officer


                                       A-1