SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, DC  20549

                                  FORM 12b-25

                                                   Commission File Number 1-9579

                          NOTIFICATION OF LATE FILING

     (Check One): [_] Form 10-K   [_] Form 11-K   [_] Form 20-F  [X] Form 10-Q

[_] Form N-SAR

     For Period Ended: July 31, 2000
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[_] Transition Report on Form 10-K           [_] Transition Report on Form 10-Q
[_] Transition Report on Form 20-F           [_] Transition Report on Form N-SAR
[_] Transition Report on Form 11-K

     For the Transition Period Ended:__________________________________________

     Read attached instruction sheet before preparing form. Please print or
type.

     Nothing in this form shall be construed to imply that the Commission has
verified any information contained herein.

     If the notification relates to a portion of the filing checked above,
identify the item(s) to which the notification relates:________________________

_______________________________________________________________________________

                                    PART I
                            REGISTRANT INFORMATION

Full name of registrant  Ecogen Inc.
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Former name if applicable

_________________________________________________________________________

Address of principal executive office (Street and number)
2000 West Cabot Boulevard #170
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City, state and zip code Langhorne, PA  19047-1811
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                                    PART II
                            RULE 12b-25 (b) and (c)

     If the subject report could not be filed without unreasonable effort or
expense and the registrant seeks relief pursuant to Rule 12b-25(b), the
following should be completed. (Check box if appropriate.)

[X]      (a) The reasons described in reasonable detail in Part III of this form
             could not be eliminated without unreasonable effort or expense;
[X]      (b) The subject annual report, semi-annual report, transition report on
             Form 10-K, 20-F, 11-K or Form N-SAR, or portion thereof will be
             filed on or before the 15/th/ calendar day following the prescribed
             due date; or the subject quarterly report or transition report on
             Form 10-Q, or portion thereof will be filed on or before the fifth
             calendar day following the prescribed due date; and
[_]      (c) The accountant's statement or other exhibit required by Rule 12b-
             25(c) has been attached if applicable.

                                   PART III
                                  NARRATIVE

     State below in reasonable detail the reasons why Form 10-K, 11-K, 20-F, 10-
Q, N-SAR or the transition report portion thereof could not be filed within the
prescribed time period. (Attach extra sheets if needed.)

Data and other information regarding certain material operations of the Company
required for the filing are not currently available and could not be made
available without unreasonable effort and expense

                                    PART IV
                               OTHER INFORMATION

     (1) Name and telephone number of person to contact in regard to this
notification

       James P. Reilly, Jr.                215               702-2500
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             (Name)                    (Area Code)      (Telephone Number)

     (2) Have all other periodic reports required under Section 13 or 15(d) of
the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act
of 1940 during the preceding 12 months or for such shorter period that the
registrant was required to file such report(s) been filed? If the answer is no,
identify report(s).
                                          [X] Yes  [_] No

     (3) Is it anticipated that any significant change in results of operations
from the corresponding period for the last fiscal year will be reflected by the
earnings statements to be included in the subject report or portion thereof?

                                          [_] Yes  [X] No

     If so: attach an explanation of the anticipated change, both narratively
and quantitatively, and, if appropriate, state the reasons why a reasonable
estimate of the results cannot be made.


                                  Ecogen Inc.
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                 (Name of Registrant as Specified in Charter)


Has caused this notification to be signed on its behalf by the undersigned
thereunto duly authorized.


Date: September 13, 2000         By: /s/ James P. Reilly, Jr.
      ------------------------       -------------------------------------------
                                     Name:  James P. Reilly, Jr.
                                     Title: Chairman and Chief Executive Officer