PPG INDUSTRIES, INC. AND THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. as Trustee THIRDSUPPLEMENTAL INDENTURE Dated August 3, 2012 to Indenture Dated as of March 18, 2008

Exhibit 4.4

PPG INDUSTRIES, INC.

AND

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.

as Trustee

THIRD SUPPLEMENTAL INDENTURE

Dated August 3, 2012

to

Indenture

Dated as of March 18, 2008

THIRD SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as August 3, 2012, between PPG INDUSTRIES, INC., a Pennsylvania corporation (the “Company”) and THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., a national banking association, as trustee (the “Trustee”).

Capitalized terms used herein and not otherwise defined herein have the meanings assigned to those terms in the Indenture unless otherwise indicated.

R E C I T A L S

WHEREAS, the Company executed and delivered an indenture dated as of March 18, 2008 (the “Indenture”) between the Company and the Trustee;

WHEREAS, the Company executed and delivered a first supplemental indenture dated as of March 18, 2008 between the Company and the Trustee;

WHEREAS, the Company executed and delivered a second supplemental indenture dated as of November 12, 2010 between the Company and the Trustee;

WHEREAS, Section 9.01 of the Indenture provides that the Company and the Trustee may enter into one or more indentures supplemental to the Indenture, without the consent of any Holders, to add, among other things, covenants and agreements of the Company to be observed thereafter for the protection of the Holders of all or any series of Securities and to establish the terms of any series of Securities;

WHEREAS, the Company desires to issue a series of Securities, the $400,000,000 2.700% Notes Due 2022 (the “Notes; and

WHEREAS, all requirements necessary to make this Supplemental Indenture a valid, binding and enforceable instrument in accordance with its terms have been done and performed, and the execution and delivery of this Supplemental Indenture has been duly authorized in all respects.

NOW, THEREFORE, in consideration of the covenants and agreements set forth herein, the parties hereto hereby agree as follows:

ARTICLE I

TERMS AND CONDITIONS

Section 1.01. Terms and Conditions. The terms and characteristics of the Notes shall be as follows (the numbered clauses set forth below corresponding to the numbered subsections of Section 3.01 of the Indenture, with terms used and not defined herein having the meanings specified in the Indenture):

“Treasury Rate” means, with respect to any redemption date, the rate per annum equal to the semiannual equivalent yield to a maturity of the Comparable Treasury Issue, assuming a price for

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the Comparable Treasury Issue (expressed as a percentage of its principal amount equal to the Comparable Treasury Price for such redemption date).

“Comparable Treasury Issue” means the United States Treasury security selected by an Independent Investment Banker as having a maturity comparable to the remaining term of the Notes to be redeemed that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such Notes.

“Comparable Treasury Price” means, with respect to any redemption date, (i) the average of the Reference Treasury Dealer Quotations, as determined by the Company, for such redemption date, after excluding the highest and lowest such Reference Treasury Dealer Quotations, or (ii) if the Company obtains fewer than four such Reference Treasury Dealer Quotations, the average of all such Quotations.

“Independent Investment Banker” means one of the Reference Treasury Dealers that the Company appoints.

“Reference Treasury Dealer” means either BNP Paribas Securities Corp., Goldman, Sachs & Co., or J.P. Morgan Securities LLC and their successors, provided, however, that if any of the foregoing ceases to be a primary U.S. Government securities dealer in New York City (a “Primary Treasury Dealer”), the Company will substitute another Primary Treasury Dealer.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any redemption date, the average, as determined by the Company, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Company by such Reference Treasury Dealer at 5:00 p.m. on the third business day preceding such redemption date.

Notice of any redemption will be mailed at least 30 days but not more than 60 days before the redemption date to each holder of Notes to be redeemed.

Unless the Company defaults in payment of the redemption price, on and after the redemption date, interest will cease to accrue on the Notes or portions thereof called for redemption.

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On each Change of Control Payment Date, the Company shall, to the extent lawful:

(A) accept for payment all Notes or portions of Notes properly tendered pursuant to the applicable Change of Control Offer;

(B) deposit with the Paying Agent an amount equal to the Change of Control Payment in respect of all Notes or portions of Notes properly tendered; and

(C) deliver or cause to be delivered to the Trustee the Notes properly accepted together with an Officers’ Certificate stating the aggregate principal amount of Notes or portions of Notes being repurchased.

The Company shall not be required to make a Change of Control Offer upon the occurrence of a Change of Control Triggering Event if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an offer made by the Company and the third party purchases all Notes properly tendered and not withdrawn under its offer. In addition, the Company shall not repurchase any Notes if there has occurred and is continuing on the Change of Control Payment Date an Event of Default, other than a default in the payment of the Change of Control Payment upon a Change of Control Triggering Event.

The Company shall comply with the requirements of Rule 14e-1 under the Exchange Act, and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable in connection with the repurchase of the Notes as a result of a Change of Control Triggering Event. To the extent that the provisions of any such securities laws or regulations conflict with the Change of Control Offer provisions of the Notes, the Company shall comply with those securities laws and regulations and shall not be deemed to have breached its obligations under the Change of Control Offer provisions herein by virtue of any such conflict.

“Change of Control” shall mean the occurrence of any of the following: (i) the direct or indirect sale, lease, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or more series of related transactions, of all

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or substantially all of the Company’s assets and the assets of the Company’s Subsidiaries, taken as a whole, to any Person, other than the Company or one of the Company’s Subsidiaries; (ii) the consummation of any transaction (including, without limitation, any merger or consolidation) the result of which is that any Person becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 under the Exchange Act), directly or indirectly, of more than 50% of the Company’s outstanding Voting Stock or other Voting Stock into which the Company’s Voting Stock is reclassified, consolidated, exchanged or changed, measured by voting power rather than number of shares; (iii) the Company consolidates with, or merges with or into, any Person, or any Person consolidates with, or merges with or into, the Company, in any such event pursuant to a transaction in which any of the Company’s outstanding Voting Stock or the Voting Stock of such other Person is converted into or exchanged for cash, securities or other property, other than any such transaction where the shares of the Company’s Voting Stock outstanding immediately prior to such transaction constitute, or are converted into or exchanged for, a majority of the Voting Stock of the surviving Person or any direct or indirect parent company of the surviving Person immediately after giving effect to such transaction; (iv) the first day on which a majority of the members of the Company’s Board of Directors are not Continuing Directors; or (v) the adoption of a plan relating to the Company’s liquidation or dissolution. The term “Person,” as used in this definition, has the meaning given thereto in Section 13(d)(3) of the Exchange Act.

“Change of Control Triggering Event” means the occurrence of both a Change of Control and a Rating Event.

“Continuing Directors” means, as of any date of determination, any member of the Company’s Board of Directors who (i) was a member of such Board of Directors on the date the Notes were issued or (ii) was nominated for election, elected or appointed to such Board of Directors with the approval of a majority of the Continuing Directors who were members of such Board of Directors at the time of such nomination, election or appointment (either by a specific vote or by approval of the Company’s proxy statement in which such member was named as a nominee for election as a director, without objection to such nomination).

“Investment Grade Rating” means a rating equal to or higher than Baa3 (or the equivalent) by Moody’s and BBB- (or the equivalent) by S&P, and the equivalent investment grade credit rating from any replacement rating agency or Rating Agencies selected by the Company.

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“Moody’s” means Moody’s Investors Service, Inc., and its successors.

“Rating Agencies” means (i) each of Moody’s and S&P; and (ii) if either Moody’s or S&P ceases to rate the Notes or fails to make a rating of the Notes publicly available for reasons outside of the Company’s control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange Act selected by the Company (as certified by a resolution of the Company’s Board of Directors) as a replacement agency for Moody’s or S&P, or all of them, as the case may be.

“Rating Event” means the rating on the Notes is lowered by each of the Rating Agencies and the Notes are rated below an Investment Grade Rating by each of the Rating Agencies on any day during the period (which period shall be extended so long as the rating of the Notes is under publicly announced consideration for a possible downgrade by any of the Rating Agencies) commencing 60 days prior to the first public notice of the occurrence of a Change of Control or the Company’s intention to effect a Change of Control and ending 60 days following consummation of such Change of Control.

“S&P” means Standard & Poor’s Rating Services, a division of The McGraw-Hill Companies, Inc., and its successors.

“Voting Stock” means, with respect to any specified “Person” (as that term is used in Section 13(d)(3) of the Exchange Act) as of any date, the capital stock of such Person that is at the time entitled to vote generally in the election of the board of directors of such Person.

ARTICLE II

MISCELLANEOUS

Section 2.01. Effect Of Supplemental Indenture. Upon the execution and delivery of this Supplemental Indenture by the Company and the Trustee, the Indenture shall be modified in accordance herewith, and this Supplemental

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Indenture shall form a part of the Indenture for all purposes; and every Holder of Securities heretofore or hereafter authenticated and delivered under the Indenture shall be bound thereby.

Section 2.02. Indenture Remains in Full Force and Effect. Except as supplemented and amended hereby, all provisions in the Indenture shall remain in full force and effect.

Section 2.03. Indenture and Supplemental Indenture Construed Together. This Supplemental Indenture is an indenture supplemental to and in implementation of the Indenture, and the Indenture and this Supplemental Indenture shall henceforth be read and construed together.

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Section 2.04. Confirmation of Indenture. The Indenture, as supplemented and amended by this Supplemental Indenture, is in all respects confirmed and ratified.

Section 2.05. Conflict with Trust Indenture Act. If any provision of this Supplemental Indenture limits, qualifies or conflicts with another provision hereof which is required to be included in this Supplemental Indenture by any of the provisions of the Trust Indenture Act, such required provision shall control.

Section 2.06. Separability. In case any one or more of the provisions contained in this Supplemental Indenture shall be invalid, illegal or unenforceable, the validity, legality or enforceability of the remaining provisions shall not in any way be affected or impaired thereby.

Section 2.07. Successors and Assigns. All agreements in this Supplemental Indenture shall be binding upon and inure to the benefit of the respective successors and assigns of the Company and the Trustee.

Section 2.08. Certain Duties and Responsibilities of the Trustee. In entering into this Supplemental Indenture, the Trustee shall be entitled to the benefit of every provision of the Indenture relating to the conduct or affecting the liability of or affording protection to the Trustee, whether or not elsewhere herein so provided. The Trustee, for itself and its successor or successors, accepts the terms of the Indenture as amended by this Supplemental Indenture, and agrees to perform the same, but only subject to the terms and provisions defining and limiting the liabilities and responsibilities of the Trustee, which terms and provisions shall in like manner define and limit its liabilities and responsibilities in the performance of the trust created by the Indenture. The Trustee makes no representations as to the validity or sufficiency of this Supplemental Indenture other than as to the validity of its execution and delivery by the Trustee. The recitals and statements herein are deemed to be those of the Company and not of the Trustee.

Section 2.09. Governing Law. This Supplemental Indenture shall be governed by, and construed in accordance with, the laws of the State of New York.

Section 2.10. Counterparts. This Supplemental Indenture may be executed in any number of counterparts by the parties hereto on separate counterparts, each of which, when so executed and delivered, shall be deemed an original, but all such counterparts shall together constitute one and the same instrument.

[Signature Page Follows]

IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly executed, as of the day and year first written above.

[Signature Page to Third Supplemental Indenture]