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                                                                      EXHIBIT 21



                   MAJOR SUBSIDIARIES OF LAFARGE CORPORATION

The following indicates the corporate names (and all other significant names,
if any, under which business is conducted) and jurisdictions of incorporation
of the subsidiaries of Lafarge Corporation, all of which are wholly owned or
majority owned. Indirect subsidiaries of Lafarge Corporation are indented and
listed following their direct parent corporations.

<TABLE>
<CAPTION>
                                                              Jurisdiction
           Name(s)                                            of Incorporation
--------------------------------------------                  ----------------
<S>                                                           <C>
American Transport Leasing, Inc.                              Delaware
Cement Transport, Ltd.                                        North Dakota
Friday Harbor Sand & Gravel Co.                               Washington
International Atlantins Insurance Company                     Vermont
Lafarge Dakota Inc.                                           North Dakota
Lafarge Florida Inc.                                          Florida
National Minerals Corporation                                 Minnesota
Systech Environmental Corporation                             Delaware
Tews Company                                                  Delaware
Walter N. Handy Co., Inc.                                     Missouri
Lafarge Canada Inc.                                           Canada
           Allan G. Cook Limited                              Ontario
           Gestion Carim Inc.                                 Quebec
           International Atlantins Agencies Inc.              British Columbia
           Johnson Concrete & Material Ltd.                   Saskatchewan
           Lulu Transport Inc.                                British Columbia
           N C Rubber Products Inc.                           Ontario
           North Western Concrete Limited                     Ontario
           Quality Ready-Mix Limited                          Ontario
           Re-Wa Holdings Ltd.                                Alberta
           Richvale York Block Inc.                           Ontario
           Les sablieres Forestville Inc.                     Quebec
           Standard Paving Maritime Limited                   Nova Scotia
           Valley Rite-Mix Ltd.                               British Columbia
</TABLE>

Lafarge Corporation also does business under the following names: Florida
Portland Cement Company, Lafarge Construction Materials, Lafarge Gypsum,
Trinity Portland Cement Company.

Lafarge Canada Inc. also does business under the following names: Alberta
Concrete Products, Apex Gravel, Bestpipe, Brunswick Ready Mix Concrete, Canada
Concrete, Capital Concrete, Challenge Concrete, Champion Concrete, Cinq
Concrete, Coldstream Concrete, Columbia Concrete, Conmac Western Industries,
Consolidated Sand & Gravel Company, Construction Chemicals, Country Building
Supplies, Crown Equipment, Crown Paving and Engineering, Duracon, Forbes Ready
Mix, Francon-Lafarge, Guelph Sand and Gravel, Great Lakes Flyash, High River
Concrete, Johnston Ready Mix, Lafarge Concrete, Lafarge Construction Materials,
Lethbridge Concrete Products, Manitoulin Precast, Maritime Cement, Masonry
Products, Nelson Aggregate Co., O.K. Construction Materials, Permanent-Lafarge,
Red-D-Mix Block, Redmond Sand & Gravel, Richvale - McCord, Richvale - York,
Rocky Mountain Precast, Spartan Explosives, Standard Aggregates, Standard
Asphalt, Supercrete, Trans-Alta Flyash.

Information regarding 60 additional subsidiaries of the Registrant has been
omitted because such subsidiaries, considered in the aggregate as a single
subsidiary, do not constitute a "significant subsidiary" as defined in Rule
1-02(v) of Regulation S-X [17 CFR 210.1-02(v)].