Exhibit 99.1

Certification Pursuant to 18 U.S.C. Section 1350, As Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the Annual Report of ProQuest Company (the “Company”) on Form 10-K for the period ending December 28, 2002 hereof (the “Report”), the undersigned Chief Executive Officer of the Company hereby certifies, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002 that based on his knowledge: 1) the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and 2) the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company as of and for the periods covered in the Report.

/s/    ALAN ALDWORTH        

Alan Aldworth, President and

Chief Executive Officer

March 27, 2003