SC TO-T/A

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

Tender Offer Statement under Section 14(d)(1) or 13(e)(1)

of the Securities Exchange Act of 1934
(Amendment No. 6)

LAFARGE NORTH AMERICA INC.

(Name of Subject Company (issuer))

EFALAR INC.

a wholly owned subsidiary of

LAFARGE S.A.

(Names of Filing Persons (Offerors))

COMMON STOCK, PAR VALUE $1.00 PER SHARE

(Title of Class of Securities)

505862-10-2

(CUSIP Number of Class of Securities)

Laurent Alpert

Cleary Gottlieb Steen & Hamilton LLP

One Liberty Plaza

New York, New York 10006

Telephone: (212) 225-2340

(Name, address, and telephone numbers of person authorized

to receive notices and communications on behalf of filing persons)

Calculation of Filing Fee

Transaction valuation*
$2,387,354,550 Amount of filing fee**
$255,446.94

*Estimated for purposes of calculating the amount of filing fee only. The calculation assumes the purchase of all outstanding shares of common stock, par value $1.00 per share, of Lafarge North America Inc., a Maryland corporation, other than the shares owned by Lafarge S.A. and its subsidiaries, at a purchase price of $75.00 per share, net to the seller in cash. As of December 31, 2005 there were 71,436,455 shares of common stock outstanding, of which 39,605,061 shares are owned by Lafarge S.A. and its subsidiaries. As a result, this calculation assumes the purchase of 31,831,394 shares.

**the amount of filing fee is calculated in accordance with Rule 240.0-11 of the Securities Exchange Act of 1934, as amended, and Fee Rate Advisory No. 5 for fiscal year 2006 issued by the Securities and Exchange Commission on November 23, 2005. Such fee equals 0.010700% of the transaction value.

x Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:	$255,446.94
Form or Registration No.:	Schedule TO-T
Filing Party:	Lafarge S.A.
Date Filed:	February 21, 2006

o Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

      Check the appropriate boxes below to designate any transactions to which the statement relates:

x           third-party tender offer subject to Rule 14d-1.

o           issuer tender offer subject to Rule 13e-4.

x           going-private transaction subject to Rule 13e-3.

o           amendment to Schedule 13D under Rule 13d-2.

SEC2559 (6-05) Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

Check the following box if the filing is a final amendment reporting the results of the tender offer:     o

TABLE OF CONTENTS

	Item 4. Terms of the Transaction.
	Item 12. Exhibits.
SIGNATURES
EXHIBIT INDEX
EX-99.A.1.XVII:

     This Amendment No. 6 amends and supplements the Tender Offer Statement and Rule 13E-3 Transaction Statement filed under cover of Schedule TO (this “Schedule TO”) with the Securities and Exchange Commission (“SEC”) on February 21, 2006, by Lafarge S.A., a French société anonyme (“Parent”) and Efalar Inc., a Delaware corporation and direct, wholly-owned subsidiary of Parent (“Purchaser”). This Schedule TO relates to the offer by Purchaser to purchase all outstanding shares of common stock, par value $1.00 per share (“Common Shares”), of Lafarge North America Inc., a Maryland corporation (the “Company”) not owned by Parent and its subsidiaries, at a purchase price of $82.00 per Common Share, net to the seller in cash, upon the terms and subject to the conditions set forth in the Offer to Purchase, dated February 21, 2006 (as amended by amendments to the Schedule TO filed by Parent with the SEC, the “Offer to Purchase”) and the related Letter of Transmittal (which, as amended or supplemented from time to time, together constitute the “Offer”).

Item 4. Terms of the Transaction.

     Section (a) of Item 4 is amended and supplemented as follows:

     The price per Common Share to be paid pursuant to the Offer is being increased from $75.00 per Common Share to $82.00 per Common Share (the “Amended Offer Price”), net to the seller in cash, without interest, upon the terms and subject to the conditions set forth in the Offer to Purchase and to be set forth in a supplement to the Offer to Purchase and in a related revised (pink) Letter of Transmittal, copies of which will be distributed to shareholders of the Company.

     The Offer is extended to, and will expire at, 12:00 midnight, New York City time, on Friday, April 28, 2006, unless the Offer is extended further.

Item 12. Exhibits.

     (a)(1)(xvii) Press Release Issued by Lafarge S.A. on April 4, 2006.

SIGNATURES

     After due 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.

LAFARGE S.A.

By: /s/ Michel Bisiaux

Michel Bisiaux

Corporate Secretary

EFALAR INC.

By: /s/ Michel Bisiaux

Michel Bisiaux

Secretary

Dated: April 4, 2006

EXHIBIT INDEX

EXHIBIT	DESCRIPTION
(a)(1)(xvii)	Press Release Issued by Lafarge S.A. on April 4, 2006.

EX-99.A.1.XVII

PRESS RELEASE

Euronext: LG, NYSE: LR Paris, April 4 2006

Lafarge increases offer for outstanding minority shares of lafarge north america to $82
per share and extends offer to april 28

Lafarge, the world leader in building materials, and owner of a 53.2% stake in Lafarge North America (NYSE & TSX: LAF), today announced that it will amend its cash tender offer (the “Offer”) for the remaining 46.8% minority stake it does not own by increasing the offer price to $82 per share. The increased offer price represents a premium of 27.6% over Lafarge North America’s closing stock price on February 3, 2006, the last trading day before Lafarge announced its intention to commence the tender offer, and a premium of 43.2% over Lafarge North America’s average closing stock price during the three months prior to the announcement of its intention to commence the tender offer.

The revised offer reflects the recent generally improved outlook for the North American building materials sector as a whole and for Lafarge North America in particular.

Lafarge believes that at the new offer price the transaction is attractive to Lafarge North America shareholders while still making sense for Lafarge and creating value for its shareholders.

Lafarge has also extended the expiration date of its offer for common shares of Lafarge North America until 12:00 midnight, New York City time, on Friday, April 28, 2006. The Offer was scheduled to expire at 12:00 midnight, New York City time, on Monday, April 3, 2006. Shareholders who have already tendered their shares will receive the increased offer price of $82 per share and need not take any additional action in order to receive such price.

The Offer is conditioned upon, among other things, the tender of a majority of the shares not held by Lafarge and its affiliates and the ownership by Lafarge of at least 90% of the outstanding shares. Any common shares not acquired in the tender offer are expected to be acquired in a subsequent merger at the same price as the tender offer.

Concurrently with the increase in the offer price for common shares of Lafarge North America, Lafarge also announced that it will increase the offer price of its cash offer for all outstanding exchangeable preference shares of Lafarge Canada Inc. (TSX: LCI.PR.E), a subsidiary of Lafarge North America Inc., to $82 per share. The term of the offer for all outstanding exchangeable preference shares of Lafarge Canada has also been extended until 12:00 midnight, New York City time, on Friday, April 28, 2006. The offer for exchangeable preference shares was also scheduled to expire at 12:00 midnight, New York City time, on April 3, 2006.

As of Monday, April 3, approximately 41,585 common shares of Lafarge North America and 28,521 exchangeable preference shares of Lafarge Canada had been tendered or committed to be tendered at the original offer price of $75.

Lafarge stated that it expected to mail promptly to shareholders of Lafarge North America a supplement to its Offer to Purchase and to amend its tender offer statement on file in with the United States Securities and Exchange Commission to reflect the increased offer price and other relevant changes.

Lafarge North America shareholders and other interested parties are urged to read the Tender Offer Statement on Schedule TO, as amended, the Offer to Purchase and any other documents relating to the tender offer that are filed with the United States Securities and Exchange Commission (the “SEC”) because they contain important information. Lafarge North America shareholders will be able to receive such documents free of charge at the SEC’s website, www.sec.gov, or by contacting Innisfree M&A Incorporated, the Information Agent for the transaction, at (877) 825-8730 for English speakers, (877) 825-8777 for French speakers or (212) 750-5833 for banks and brokers calling collect.

Note to Editors:

Lafarge is the world leader in building materials, with top-ranking positions in all four of its businesses: Cement, Aggregates & Concrete, Roofing and Gypsum. With 80,000 employees in 75 countries, Lafarge posted sales of Euros 16 billion in 2005. Lafarge has been committed to sustainable development for many years, pursuing a strategy that combines industrial know-how with performance, value creation, respect for employees and local cultures, environmental protection and the conservation of natural resources and energy. Lafarge is the only company in the construction materials sector to be listed in the 2006 ‘100 Global Most Sustainable Corporations in the World’. To make advances in building materials, Lafarge places the customer at the heart of its concerns. It offers the construction industry and the general public innovative solutions bringing greater safety, comfort and quality to their everyday surroundings. Additional information is available on the web site at www.lafarge.com.

Lafarge North America is one of the largest publicly traded construction materials providers in North America. Lafarge North America today is a 53.2%-owned subsidiary of Lafarge.

Contacts:

COMMUNICATIONS	INVESTOR RELATIONS
Stéphanie Tessier:	Yvon Brind’Amour:
33-1 44-34-92-32	33-1 44-34-11-26
stephanie.tessier@lafarge.com	yvon.brindamour@lafarge.com
Lucy Wadge:	Danièle Daouphars:
33-1 44-34-19-47	33-1 44-34-11-51
lucy.wadge@lafarge.com	daniele.daouphars@lafarge.com
Louisa Pearce-Smith:
33-1 44-34-18-18
louisa.pearce-smith@lafarge.com

Statements made in this press release that are not historical facts, including the expected immediacy of earnings accretion, the improved use of free cash flow and increased flexibility and efficiency in implementing its North American strategy, are forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements are not guarantees of future performance and involve risks, uncertainties and assumptions (“Factors”), which are difficult to predict. Some of the Factors that could cause actual results to differ materially from those expressed in the forward-looking statements include, but are not limited to: whether the conditions of the tender offer will be satisfied; the cyclical nature of the Company’s business; national and regional economic conditions in the countries in which the Company does business; currency fluctuations; seasonal nature of the Company’s operations; levels of construction spending in major markets and, in particular, in North America; supply/demand structure of the industry; competition from new or existing competitors; unfavorable weather conditions during peak construction periods; changes in and implementation of environmental and other governmental regulations; our ability to successfully identify, complete and efficiently integrate acquisitions; our ability to successfully penetrate new markets; and other Factors disclosed in the Company’s public filings with the French Autorité des Marchés Financiers and the US Securities and Exchange Commission including the Company’s Reference Document and Annual Report on Form 20-F. In general, the Company is subject to the risks and uncertainties of the construction industry and of doing business throughout the world. The forward-looking statements are made as of this date and the Company undertakes no obligation to update them, whether as a result of new information, future events or otherwise.