11% SENIOR SUBORDINATED NOTES DUE 2007 THE DIALOG CORPORATION PLC NOTICE OF GUARANTEED DELIVERY OF 11% SENIOR SUBORDINATED NOTES DUE 2007 This form, or a form substantially equivalent to this form, must be used to accept the Offer (as defined below) if certificates for the principal amount of 11% Senior Subordinated Notes due 2007 (the "Notes") are not immediately available, if the procedure for book-entry transfer cannot be completed on a timely basis, or if time will not permit all other documents required by the Consent and Letter of Transmittal to be delivered to The Bank of New York, as Depositary, on or prior to the expiration of the Offer. Such form may be delivered by hand or transmitted by mail, or by facsimile transmission, to the Depositary. See Section 8--"Procedures for Tendering Notes and Delivering Consents" in the Statement (as defined below). The Eligible Institution (as defined below) which completes this form must communicate the guarantee to the Depositary and either the Consent and Letter of Transmittal and certificates for Notes must be delivered to the Depositary or the Depositary must receive confirmation of book-entry transfer of the Notes to the Depositary's account at The Depository Trust Company within three New York Stock Exchange trading days after the Expiration Date (as defined in the Statement). Failure to do so could result in a financial loss to such Eligible Institution. TO: THE BANK OF NEW YORK, DEPOSITARY BY OVERNIGHT COURIER BY MAIL: AND BY HAND AFTER 4:30 P.M.: BY HAND BEFORE 4:30 P.M.: The Bank of New York The Bank of New York The Bank of New York 101 Barclay Street 7E 101 Barclay Street 7E 101 Barclay Street 7E New York, NY 10286 New York, NY 10286 New York, NY 10286 Attention: Carolle Montreuil Attention: Carolle Montreuil Attention: Carolle Montreuil BY FACSIMILE (212) 815-6339 FOR ELIGIBLE INSTITUTIONS ONLY CONFIRM BY TELEPHONE (for Confirmation Only) (212) 815-5788 Delivery of this instrument to an address other than as set forth above or transmission of instructions via a facsimile number other than one listed above will not constitute a valid delivery. This form is not to be used to guarantee signatures. If a signature on the Consent and Letter of Transmittal is required to be guaranteed by an Eligible Institution under the instructions thereto, such signature guarantee must appear in the applicable space provided in the signature box on the Consent and Letter of Transmittal. Ladies and Gentlemen: The undersigned hereby tenders to The Dialog Corporation plc, a company incorporated in England and Wales (the "Company"), upon the terms and subject to the conditions set forth in the Offer to Purchase, dated March 24, 2000 (the "Offer to Purchase"), and the Consent and Letter of Transmittal (which together with the Offer to Purchase, constitutes the "Offer"), receipt of which hereby is acknowledged, the principal amount of 11% Senior Subordinated Notes due 2007 (the "Notes") of the Company, listed below, pursuant to the guaranteed delivery procedure set forth in Section 8--"Procedures for Tendering Notes and Delivering Consents" in the Offer to Purchase and Consent Solicitation Statement, dated March 24, 2000 (the "Statement"). - ------------------------------------------------------------------------------------------ Principal Amount of Notes Signature - ------------------------------------------------------------------------------------------ Certificate Nos. (if available): Name(s) of Record Holder(s): (Please Print) - ------------------------------------------------------------------------------------------ If Notes will be tendered Address: by book-entry transfer: Name of Tendering Institution: - ------------------------------------------------------------------------------------------ Account No. at The Depositary Trust Company Area Code and Telephone Number: - ------------------------------------------------------------------------------------------ GUARANTEE (NOT TO BE USED FOR SIGNATURE GUARANTEE) The undersigned, a bank, broker, dealer, credit union, savings association, or other entity which is a member in good standing of the Securities Transfer Agents Medallion Program, the New York Stock Exchange Medallion Signature Guarantee Program, the Stock Exchange Medallion Program, or a bank, broker, dealer, credit union, savings association, or other entity which is an "eligible guarantor institution," as such term is defined in Rule 17Ad-15 under the Securities Exchange Act of 1934, as amended (each an "Eligible Institution"), guarantees to deliver to the Depositary at one of its addresses set forth above (i) certificate(s) for the Notes tendered hereby, in proper form for transfer, together with a properly completed and duly executed Consent(s) and Letter(s) of Transmittal, with any required signature. Notes tendered hereby into the Depositary's account at The Depository Trust Company, all within three New York Stock Exchange trading days after the Expiration Date. - ------------------------------------------- ------------------------------------------- Name of Firm Authorized Signature - -------------------------------------------- -------------------------------------------- Address Name - -------------------------------------------- -------------------------------------------- City, State, Zip Code Title - -------------------------------------------- Area Code and Telephone Number - -------------------------------------------- Date: __________________________________________, 2000 DO NOT SEND CERTIFICATES WITH THIS FORM. YOUR CERTIFICATES MUST BE SENT WITH THE CONSENT AND LETTER OF TRANSMITTAL.