Exhibit (a)(1)(C)

THIS DOCUMENT IS IMPORTANT AND REQUIRES YOUR IMMEDIATE ATTENTION

If you are in any doubt about the Offer or the action you should take, you should immediately seek independent financial advice from your stockbroker, bank manager, solicitor, accountant or other independent financial advisor duly authorized under the Financial Services Act 1986.

If you have sold or otherwise transferred all of your A Ordinary Shares, £8.00 par value per share (the “A Ordinary Shares”), and Ordinary Shares, $0.01 par value per share (the “Ordinary Shares,” and together with the A Ordinary Shares, the “Shares”), please send this Form and the enclosed reply-paid envelope, together with the accompanying Offer To Purchase, dated December 19, 2003 (the “Offer To Purchase”), and any accompanying documents, at once to Parker-Hannifin Corporation, an Ohio corporation (“Parker”), or the transferee or to the stockbroker, bank or other agent through whom the sale or transfer was effected for delivery to Parker or transferee. However, the Offer To Purchase is not being made directly or indirectly in or into Canada, Japan or Australia and this Form, the Offer To Purchase, and any other documents related to the Offer To Purchase should not be distributed, forwarded or transmitted in or into those countries or into any other jurisdiction if doing so would constitute a violation of that jurisdiction’s relevant laws. Holders of Shares, including nominees, trustees and custodians, who may have an obligation, or who otherwise intend, to forward this Form or the Offer To Purchase outside the United States or the United Kingdom should read the further details in this regard, which are contained in Section 22 — “Overseas Shareholders” of the Offer To Purchase, before doing so.

This Form should be read in conjunction with the accompanying Offer To Purchase. Unless the context otherwise requires, the definitions contained in the Offer To Purchase also apply in this Form. The provisions of the Offer To Purchase, in so far as they relate to the Offer, are deemed to be incorporated in this Form and to be part of this Form and should be read carefully by each holder of Shares.

FORM OF ACCEPTANCE

in connection with the Recommended Cash Offer

by

Parker-Hannifin Corporation

for

Denison International plc

Acceptances of the Offer must be received by 8:00 a.m., New York City time, on Thursday, January 22, 2004

ACTION TO BE TAKEN

If you are in any doubt as to how to fill in this Form, please contact Georgeson Shareholder Communications Inc. at (800) 843-9819 (toll free in the United States) and 00-800-3333-44-33 (toll free in Europe).

DO NOT DETACH ANY PART OF THIS FORM

HOW TO COMPLETE THIS FORM

Please make sure your acceptance is received by 8:00 a.m., New York City time, on Thursday, January 22, 2004

2

PLEASE COMPLETE AS EXPLAINED ON PAGES 2, 4, 5 AND 6 IN BLOCK CAPITALS

3

ADDITIONAL NOTES REGARDING THE COMPLETION AND LODGING OF THIS FORM

In order to avoid inconvenience and delay, the following points may assist you:

Send this Form by the quickest means (e.g., airmail) to the holder (but not in or into Canada, Japan or Australia) for execution or, if he/she has executed a power of attorney, have this Form signed by the attorney in the presence of a witness who must also sign this Form. In the latter case, the original power of attorney (or a copy thereof duly certified in accordance with the Powers of Attorney Act 1971) must be lodged with this Form for noting. No other signatures are acceptable. The power of attorney will be noted by an attorney in the United Kingdom, if the accepting shareholder is a non-U.S. holder, or a notary public in the United States, if the accepting shareholder is a U.S. shareholder, and returned as directed.

If you have sold or transferred all of your holding of A Ordinary Shares or Ordinary Shares, you should at once pass this Form with the accompanying documents to Parker or the transferee or to the stockbroker, bank or other agent through whom the sale or transfer was effected for transmission to Parker or the transferee (but not in or into Canada, Japan or Australia or into any other jurisdiction if doing so would constitute a violation of that jurisdiction’s relevant laws). If your A Ordinary Shares or Ordinary Shares are in certificated form, and you wish to sell or transfer part of your holding of A Ordinary Shares or Ordinary Shares and also wish to accept the Offer in respect of the balance but are unable to obtain the balance share certificate by January 22, 2004, you should ensure that the stockbroker, bank or other agent through whom you make the sale or transfer obtains the appropriate endorsement or indication, signed on behalf of Denison’s registrars, Masters House in the United Kingdom, if the accepting shareholder is a non-U.S. holder, or Mellon Investor Services LLC in the United States, if the accepting shareholder is a U.S. shareholder, in respect of the balance of your holding of Shares.

A grant of probate or letters of administration must be obtained in respect of the relevant A Ordinary Shares or Ordinary Shares. If the grant of probate or letters of administration has/have been registered with Denison’s registrar, this Form must be signed by the personal representative(s) of the deceased holder in the presence of a witness who must also sign this Form. This Form should then be lodged with Mellon Investor Services LLC, as receiving agent, together with the relevant share certificate(s) and/or other document(s) of title. If the grant of probate or letters of administration has/have not been registered with Denison’s registrar, the personal representative(s) or the prospective personal representative(s) should sign this Form each in the presence of a witness (who must also sign this Form) and forward it to Mellon Investor Services LLC, together with the relevant share certificate(s) and/or other document(s) of title. However, once obtained, the grant of probate or letters of administration must be lodged with Mellon Investor Services LLC, as receiving agents before the consideration due under the Offer can be forwarded to the personal representative(s).

The completed Form should be signed by all the surviving joint holders in the presence of a witness who must also sign this Form. This Form should then be lodged with Mellon Investor Services LLC, accompanied by the relevant share certificate(s) and/or other document(s) of title, the death certificate, and the grant of probate or letters of administration in respect of the deceased joint holder.

You should complete this Form and if the certificate(s) and/or other documents of title is/are readily available, arrange for this Form to be lodged by such agent with Mellon Investor Services LLC, accompanied by the share certificate(s) and/or other

4

document(s) of title. If the certificates and/or other document(s) of title is/are not readily available, this completed and executed Form should be lodged with Mellon Investor Services LLC accompanied by a note saying “Certificate(s) to follow.” You should instruct your agent to forward your share certificate(s) and/or other document(s) of title to Mellon Investor Services LLC, as soon as possible thereafter. It will be helpful for your agent (unless he is in Canada, Japan or Australia) to be informed of the full terms of the Offer.

Complete and execute this Form and lodge it and any share certificate(s) and/or other document(s) of title which are available, together with a letter of explanation stating that the balance will follow (and, if applicable, that one or more of your share certificates have been lost, stolen or destroyed), with Mellon Investor Services LLC. At the same time you should write to Denison’s registrar, Masters House in the United Kingdom, 107 Hammersmith Road, London W14 0QH if the accepting shareholder is a non-U.S. holder, or Mellon Investor Services LLC, in the United States, at 85 Challenger Road, 2nd Floor, Ridgefield Park, NJ 07660, if the accepting shareholder is a U.S. Shareholder, requesting a letter of indemnity for the lost share certificate(s) and/or other document(s) of title. When completed in accordance with the instructions given, you should return the letter of indemnity to Mellon Investor Services LLC, as receiving agent, as soon as possible thereafter.

NOTE: Duly completed Forms certified by Denison’s registrars, Masters House in the United Kingdom, if the accepting shareholder is a non-U.S. holder, or Mellon Investor Services LLC in the United States, if the accepting shareholder is a U.S. shareholder, to the effect that the A Ordinary Shares or Ordinary Shares referred to therein are shares in respect of which the acceptor(s) is/are unconditionally entitled immediately to become the registered holder(s) will be treated as valid even though no share certificate(s) and/or other document(s) of title is/are delivered.

This completed and executed Form, together with the share certificate(s) and/or other document(s) of title, should be lodged with Mellon Investor Services LLC, at either of the addresses given at the foot of this page, accompanied by the original power of attorney (or a copy thereof duly certified in accordance with the Powers of Attorney Act 1971). The power of attorney will be noted by an attorney in the United Kingdom, if the accepting shareholder is a non-U.S. holder, or a notary public in the United States, if the accepting shareholder is a U.S. shareholder, and returned as directed.

Name on the certificate(s) John Smith

Correct name John Edward Smyth

Complete this Form and lodge it with Mellon Investor Services LLC, with your share certificate(s) and/or other document(s) of title and accompanied by a letter from your bank, stockbroker or solicitor confirming that the person in whose name the shares are registered is the same as the person who has signed this Form.

This Form should be completed in your new name and lodged with Mellon Investor Services LLC, with your share certificate(s) and/or other document(s) of title, and accompanied by evidence of the change of name for noting, e.g., a certified copy of the marriage certificate or deed poll or, in the case of a company, a copy of the certificate of incorporation (or equivalent) on change of name.

Complete this Form, inserting the correct address in Box 3.

Please refer to Sections 3 — “Procedure for Tendering Shares” and 22 — “Overseas Shareholders” contained in the Offer To Purchase.

5

To prevent backup federal income tax withholding of 28% of the payments made to Shareholders with respect to the purchase price of ADSs purchased pursuant to the Offer or the Compulsory Acquisition (as defined in the Offer To Purchase), a Shareholder must provide the Depositary with its correct taxpayer identification number (“TIN”) and certify that it is not subject to backup federal income tax withholding by completing the Substitute Form W-9 included in this Form of Acceptance. To prevent possible erroneous backup withholding, an exempt holder must enter its correct TIN in Part 1 of Substitute Form W-9, write “Exempt” in Part 2 of such form, and sign and date the form. See the enclosed Guidelines for Certification of Taxpayer Identification Number on Substitute Form W-9 (the “W-9 Guidelines”) for additional instructions. A Non-U.S. holder (as defined in the Offer To Purchase) must certify as to its foreign status or otherwise establish an exemption. If the Depositary is not provided with the correct TIN, the Internal Revenue Service may subject the Shareholder or other payee to penalties, and the gross proceeds of any payments that are made to such Shareholder or other payee with respect to A Ordinary and/or Ordinary Shares purchased pursuant to the Offer may be subject to 28% backup U.S. federal income tax withholding.

Certain Shareholders (including, among others, all corporations and certain foreign individuals and entities) are not subject to backup withholding. Foreign shareholders should complete and sign a Form W-8, signed under penalties of perjury, attesting to that individual’s foreign status. A Form W-8 can be obtained from the Depositary. Each Shareholder should consult his or her tax advisor as to his or her qualifications for an exemption from backup withholding and the procedure for obtaining such exemption.

If backup withholding applies, the Depositary is required to withhold 28% of any such payments made to the Shareholder or other payee. Backup withholding is not an additional tax, but merely an advance payment, which may be refunded to the extent it results in an overpayment of tax, provided the required information is furnished to the Internal Revenue Service.

If you do not have a TIN, consult the W-9 Guidelines for instructions on applying for a TIN, write “Applied For” in the space for the TIN in Part 1 of the Substitute Form W-9, and sign and date the Substitute Form W-9 and the Certificate of Awaiting Taxpayer Identification Number set forth herein. For interest and dividend payments, and certain payments made with respect to readily tradable instruments, generally you will have 60 days to get a TIN and give it to the requester before you are subject to backup withholding on payments. The 60-day rule does not apply to other types of payments. You will be subject to backup withholding on all such payments until you provide your TIN to the requester. Note: writing “Applied for” on the Substitute Form W-9 means that you have already applied for a TIN or that you intend to apply for one in the near future.

The consideration payable under the Offer cannot be sent to you until all relevant documents have been properly completed, executed and lodged by post or by hand (during normal business hours) with Mellon Investor Services LLC. Parker reserves the right, in its absolute discretion, to treat as valid any acceptance of the Offer which is not entirely in order or which is not accompanied (as appropriate) by the relevant share certificate(s) and/or other document(s) of title.

6

TO BE COMPLETED BY TENDERING SHAREHOLDERS OF SECURITIES

(See Instruction 12)

You must cross out Part 2 above if you have been notified by the IRS that you are subject to backup withholding

because of underreporting interest or dividends on your tax return.

YOU MUST COMPLETE THE FOLLOWING CERTIFICATE IF YOU WROTE “APPLIED FOR”

IN PART 1 OF SUBSTITUTE FORM W-9.

7