EXHIBIT 99.1 [THE DIALOG CORPORATION PLC LETTERHEAD] News Announcement For Immediate Release DIALOG CORPORATION CHANGES NASDAQ NATIONAL MARKET SYMBOL TO "DIAL" - CHANGE EFFECTIVE TODAY - Cary, NC and London, England - April 27, 1999: The Dialog Corporation plc ("Dialog") (NASDAQ:DIAL; LSE:DLG), a leading provider of Internet-based information, technology and eCommerce solutions to the corporate market, today announced that effective with the commencement of Nasdaq trading today, Tuesday, April 27th, the Company's Nasdaq National Market trading symbol has changed to "DIAL" from "DIALY." The symbol change is in keeping with recent revisions in Nasdaq's trading symbol procedures for foreign-based companies. Dialog requested the change in order to simplify trading and obtaining stock quotations as well as to more closely align Dialog's trading symbol with the four-letter symbols of the majority of Nasdaq National Market-traded companies. THE DIALOG CORPORATION PLC The Dialog Corporation plc (http://www.dialog.com) is a leading provider of Internet-based information, technology and eCommerce solutions to the corporate market, created by the merger of M.A.I.D plc and Knight-Ridder Information Inc. Dialog provides a range of technologies and services for Internet and intranet-based knowledge management and eCommerce applications. The company's InfoSort indexing technology is widely perceived to offer an industry standard for information categorisation, while the DIALOG, DataStar and Profound range of products and services provide comprehensive, authoritative sources of information to professionals worldwide. The Dialog Corporation has world headquarters in London and US headquarters in Cary, NC. Its American Depositary Shares (ADS) are traded on NASDAQ under the symbol "DIAL" with four Ordinary Shares comprising one ADS; its Ordinary Shares trade on the London Stock Exchange under the symbol "DLG." CONTACTS: Kristian Talvitie, U.S. Investor Relations kristian_talvitie@dialog.com 212/381-1824 Julia Morton, U.K. Investor Relations julia_morton@dialog.com 011-44-171-930-6900 Tracey Johnston, Corporate PR Manager tracey_johnston@dialog.com 011-44-171-930-6900 David C. Collins/Robert L. Rinderman dial@jcir.com Jaffoni & Collins Incorporated 212/835-8500 # # #