<PAGE>
---------------------------------
OMB APPROVAL
---------------------------------
OMB Number: 3235-0145
Expires: December 31, 1997
Estimated average burden
hours per response . . . 14.90
---------------------------------
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. 1)*
-
Discreet Logic Inc.
- --------------------------------------------------------------------------------
(Name of Issuer)
Common Shares, without par value
- --------------------------------------------------------------------------------
(Title of Class of Securities)
25467V 10 4
------------------------------
(CUSIP Number)
*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
Page 1 of 6 Pages
<PAGE>
- ------------------------ --------------------
CUSIP No. 25467V 10 4 13G Page 2 of 6 Pages
----------- --------------------
- ------------------------
- -------------------------------------------------------------------------------
1 NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
Thomas Cantwell ###-##-####
- -------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [_]
(b) [_]
- -------------------------------------------------------------------------------
3 SEC USE ONLY
- -------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- -------------------------------------------------------------------------------
5 SOLE VOTING POWER
3,248,667
NUMBER OF ---------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY
OWNED BY
EACH ---------------------------------------------------
REPORTING 7 SOLE DISPOSITIVE POWER
PERSON
WITH 3,248,667
---------------------------------------------------
8 SHARED DISPOSITIVE POWER
- -------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,248,667
- -------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
[_]
- -------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
11.62%
- -------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON *
- -------------------------------------------------------------------------------
*SEE INSTRUCTIONS BEFORE FILLING OUT!
Page 2 of 6 Pages
<PAGE>
Item 1.
(a) Name of Issuer.
--------------
Discreet Logic Inc. (the "Issuer")
(b) Address of Issuer's Principal Executive Offices.
-----------------------------------------------
5505 Boulevard St. Laurent
Suite 5200
Montreal, Quebec, Canada
M2T 1S6
Item 2.
(a) Name of Person Filing.
---------------------
Thomas Cantwell
(b) Address of Principal Business Office, or, if none, Residence.
------------------------------------------------------------
399 Ann Arbor
Houston, Texas 77062
(c) Citizenship.
-----------
Mr. Cantwell is a citizen of the United States
(d) Title of Class of Securities.
----------------------------
Common Shares, without par value (the "Common Shares").
(e) CUSIP Number.
------------
25467V 10 4
Item 3. If this statement if filed pursuant to Rule 13d-1(b), or 13d-2(b),
check whether the person filing is a:
(a) __ Broker or Dealer registered under Section 15 of the Act
(b) __ Bank as defined in Section 3(a)(6) of the Act
(c) __ Insurance Company as defined in Section 3(a)(19) of the Act
(d) __ Investment Company registered under Section 8 of the
Investment Company Act
Page 3 of 6 Pages
<PAGE>
(e) __ Investment Advisor registered under Section 203 of the
Investment Advisers Act of 1940
(f) __ Employee Benefit Plan, Pension Fund which is subject to the
provisions of the Employee Retirement Income Security Act of
1974 or Endowment Fund; see Section 240.13d-1(b)(1)(ii)(F)
(g) __ Parent Holding Company, in accordance with Section
240.13d-1(b)(ii)(G) (Note: See Item 7)
(h) __ Group, in accordance with Section 240.13d-1(b)(1)(ii)(H)
Not applicable.
Item 4. Ownership.
(a) Amount Beneficially Owned.
-------------------------
As of December 31, 1996, Mr. Cantwell beneficially owned 3,248,667
Common Shares.
(b) Percent of Class.
----------------
11.62%. The foregoing percentage is calculated based on the
27,955,046 Common Shares reported to be outstanding in the Issuer's Form 10-Q
for the period ended October 31, 1996.
(c) Number of shares as to which such person has:
--------------------------------------------
(i) sole power to vote or to direct the vote:
----------------------------------------
3,248,667 shares
(ii) shared power to vote or to direct the vote:
------------------------------------------
0 shares
(iii) sole power to dispose or to direct the disposition of:
-----------------------------------------------------
3,248,667 shares
Page 4 of 6 Pages
<PAGE>
(iv) shared power to dispose or to direct the disposition of:
-------------------------------------------------------
0 shares
Item 5. Ownership of Five Percent or Less of a Class.
Not applicable.
Item 6. Ownership of More than Five Percent on Behalf of Another Person.
Not applicable.
Item 7. Identification and Classification of the Subsidiary Which
Acquired the Security Being Reported on By the Parent Holding Company.
Not applicable.
Item 8. Identification and Classification of Members of the Group.
Not applicable.
Item 9. Notice of Dissolution of Group.
Not applicable.
Item 10. Certification.
Not applicable.
This statement on Schedule 13G is not filed pursuant to Rule 13d-1(b).
Page 5 of 6 Pages
<PAGE>
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.
Dated: February 7, 1997
/s/ Thomas Cantwell
-------------------------------
Thomas Cantwell
Page 6 of 6 Pages