UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the
Securities Exchange Act of 1934

~~May 31~~June 26, 2007

Date of report (Date of earliest event reported)

PQ CORPORATION (Exact Name of Registrant as Specified in Charter)

(Exact Name of Registrant as Specified in Charter)

Pennsylvania		333-125750		23-0972750
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(IRS Employer Identification No.)

1200 West Swedesford Road

Berwyn, Pennsylvania 19312

(Address of Principal Executive Offices) (Zip Code)

(610) 651-4200

(Registrant’s telephone number, including area code)

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

~~Item~~ITEM 1.01. ENTRY INTO ~~Entry~~A ~~into~~MATERIAL aDEFINITIVE ~~Material Definitive Agreement.~~AGREEMENT

On ~~May~~June 3125, 2007, ~~our~~PQ ~~parent company, Niagara Holdings, Inc., a Delaware corporation~~ Corporation (the “~~Parent~~Company”), entered into an ~~Agreement and Plan of Merger (the “Merger~~amendment ~~Agreement”) with CPQ Holdings LLC, a Delaware limited liability company~~ (the “~~Buyer”),~~Third ~~CPQ Acquisition Corporation, a Delaware corporation and direct, wholly-owned subsidiary of Buyer (“Merger Sub~~Amendment”), ~~and J.P. Morgan Partners (BHCA), L.P., solely in its capacity as seller representative, pursuant~~ to ~~which,~~the ~~among other things, our Parent will be acquired for aggregate merger consideration to our Parent~~Company’s ~~stockholders~~Credit ~~of approximately $1.515 billion~~Agreement, ~~subject~~dated toas ~~a post-closing net working capital adjustment, less an amount equal to the sum~~ of ~~the transaction expenses payable by our Parent~~February ~~and~~11, ~~the indebtedness of our Parent and its subsidiaries outstanding immediately prior to the closing (which will be repaid as described below)~~2005, ~~plus~~among ~~the~~PQ ~~amount of cash and cash equivalent held by us and our subisidiaries immediately prior to closing. Under the terms of the Merger Agreement~~Corporation, ~~Merger~~Niagara ~~Sub will merge with and into our Parent with our Parent continuing as the surviving corporation and a direct~~Holdings, ~~wholly-owned subsidiary of the Buyer (the “Merger”)~~Inc. ~~The~~ ~~Buyer~~ and ~~Merger~~the ~~Sub~~lenders ~~are controlled by~~party ~~Carlyle~~thereto ~~Partners IV, L.P.~~ (the “~~Fund~~Credit Agreement”)~~, a private investment fund affiliated with The Carlyle Group~~. The ~~Board of Directors of our Parent~~ ~~recommended~~Third ~~the~~Amendment ~~approval~~amended of the ~~Merger~~Credit Agreement ~~and~~to permit the ~~Merger~~Company to ~~the~~commence ~~stockholders~~a oftender ~~our~~offer ~~Parent,~~ and ~~stockholders~~consent ofsolicitation ~~our~~for ~~Parent~~any ~~controlling~~and ~~a majority~~all of ~~the~~its ~~shares~~$275.0 ~~eligible~~million in toaggregate ~~vote~~principal ~~approved~~amount ~~the~~of ~~Merger~~its ~~Agreement~~7½% ~~and~~Senior ~~the Merger~~Subordinated byNotes ~~written~~due ~~consent in accordance with Delaware law~~2013.

~~At the effective time of the Merger, each outstanding share of the Class~~ A ~~Common~~copy ~~Stock or Class B Common Stock~~ of ~~our Parent, other than any shares owned by our Parent,~~ the ~~Buyer~~Third orAmendment ~~Merger~~is ~~Sub~~filed or as ~~otherwise~~Exhibit ~~agreed between Parent and any stockholder, will be cancelled and~~10.1 ~~converted into the right~~ to ~~receive~~this aCurrent ~~specific~~Report ~~amount~~on ofForm ~~cash~~8-K ~~merger consideration,~~and asis ~~described~~incorporated inherein ~~the Merger Agreement~~by reference.

~~The Buyer~~ITEM and Merger Sub have obtained equity and debt financing commitments for the transactions contemplated by the Merger Agreement, the aggregate proceeds of which will be sufficient for the Buyer and Merger Sub to pay the aggregate merger consideration, repay existing indebtedness of our Parent and all of its subsidiaries and pay the Buyer’s and Merger Sub’s fees and expenses related to the Merger8. ~~These~~01 OTHER equity and debt financing commitments are subject to customary conditions. Pursuant to the Merger Agreement, we and Parent have agreed to use our commercially reasonable efforts to discharge all of our outstanding senior subordinated notes (the “PQ Notes”) issued pursuant to the Indenture dated February 11, 2005 between Niagara Acquisition, Inc. (now known as PQ Corporation) and Wells Fargo Bank, National Association (the “Indenture”) and the notes issued by Parent (the “Mezzanine Notes” and, along with the PQ Notes, the “Notes”) pursuant to the Note Purchase Agreement, dated December 15, 2005, among Parent and the various purchasers that are parties thereto (the “Note Purchase Agreement”) by either conducting a tender offer for the Notes or effecting the redemption of the Notes in accordance with the terms of the Indenture or the Note Purchase Agreement, as applicable.EVENTS

~~The Merger~~On ~~Agreement~~June ~~provides that~~26, ~~upon termination under specified circumstances~~2007, ~~Buyer~~ ~~would be required to pay a termination fee to~~ the ~~Parent~~Company ~~equal~~issued ~~to $60 million. The Fund has agreed to guarantee~~ the ~~termination~~following ~~fee payable by Buyer to the Parent.~~press release:

~~Consummation of~~PQ ~~the~~CORPORATION ~~Merger~~COMMENCES isTENDER ~~subject~~OFFER toAND ~~customary closing conditions, including the~~CONSENT ~~expiration~~SOLICITATION orFOR ~~termination~~ANY ofAND ~~the~~ALL ~~applicable~~OF ~~waiting~~ITS ~~period~~7½% ~~under~~SENIOR ~~the~~SUBORDINATED ~~Hart-Scott-Rodino Antitrust~~NOTES ~~Improvements~~DUE ~~Act of 1976 and other competition approvals required to be obtained. The parties expect to close the transaction during the third quarter of 2007.~~2013

~~The~~Berwyn, ~~foregoing~~PA ~~summary~~– ofJune 26, 2007 – PQ Corporation (the ~~Merger~~“Company”) ~~Agreement~~today ~~and~~announced that it has commenced a cash tender offer (the ~~transactions~~“Tender ~~contemplated~~Offer”) and related consent ~~thereby~~solicitation ~~does~~(the ~~not~~“Consent ~~purport~~Solicitation” toand, betogether ~~complete~~with the Tender Offer, the “Offer”) for any and all of its $275.0 million in aggregate principal amount of its 7½% Senior Subordinated Notes due 2013 (the “Notes”). The Company is ~~subject~~making the Offer in order to satisfy the obligations of Niagara Holdings, Inc. (“Niagara”), the Company’s direct parent, under the Agreement and ~~qualified~~Plan inof ~~its~~Merger, dated as of May 31, ~~entirety~~2007, by and among Niagara, CPQ Holdings LLC, CPQ Acquisition Corporation (“Merger Sub”) and J.P. Morgan Partners (BHCA), L.P., solely in its capacity as seller representative, providing for the ~~full~~merger ~~text~~(the “Merger”) of Merger Sub with and into Niagara. The Offer is being made pursuant to an Offer to Purchase and Consent Solicitation Statement dated June 26, 2007 (the ~~Merger~~“Offer ~~Agreement~~to ~~attached~~Purchase”), aswhich ~~Exhibit~~more 2fully sets forth the terms and conditions of the Offer.1.

AsThe aConsent ~~result~~Solicitation ofwill ~~the~~expire ~~Merger~~at 5:00 p.m., ifNew York City time, on July 10, 2007, unless extended or terminated (as such date and ~~when~~time itmay ~~occurs~~be extended from time to time, wethe “Consent Payment Deadline”), and the Tender Offer will ~~become~~expire at anMidnight, ~~indirect~~New York City time, ~~wholly-owned~~on July 24, 2007, unless extended or ~~subsidiary~~terminated of(as such date and time may be extended from time to time, the ~~Buyer~~“Expiration Time”).

~~The Merger Agreement has been included to provide~~As ~~investors~~described ~~and~~in ~~security~~the ~~holders~~Offer ~~with information regarding its terms. It is not intended~~ to ~~provide any other factual information about us or our Parent. The representations~~Purchase, ~~warranties and covenants contained in~~ the ~~Merger~~total ~~Agreement were~~consideration ~~made only~~ for ~~purposes~~each ~~of such agreement and as of specific dates~~$1, ~~were~~000 ~~solely~~principal ~~for~~amount ~~the benefit~~ of ~~the~~Notes ~~parties~~validly totendered ~~such agreement,~~ and ~~may~~purchased bein ~~subject to limitations agreed upon by~~ the ~~contracting~~Offer ~~parties,~~will ~~including~~be ~~being qualified~~a byprice ~~confidential~~determined ~~disclosures~~by ~~exchanged~~reference ~~between~~to the ~~parties~~bid-side inyield ~~connection~~to ~~with the~~maturity ~~execution~~ of the ~~Merger~~3% ~~Agreement~~U. ~~The representations and warranties may~~S. ~~have~~Treasury ~~been~~Note ~~made~~due ~~for~~February ~~the~~15, ~~purposes~~2009 ~~of allocating contractual risk between the parties to the Merger Agreement instead of establishing these matters~~ as ~~facts, and may be subject to standards~~ of ~~materiality~~2:00 ~~applicable to the contracting parties that differ from those applicable to investors~~p.m., ~~Investors~~New ~~are~~York ~~not third-party~~City ~~beneficiaries~~time, ~~under the Merger Agreement and should not rely~~ on ~~the~~ ~~representations~~July 10, ~~warranties~~2007, ~~and~~unless ~~covenants~~extended ~~or any descriptions thereof~~ (as ~~characterizations~~ ofsuch ~~the~~date ~~actual~~and ~~state~~time ofmay ~~facts~~be orextended ~~condition~~from ~~of our Parent or~~time ~~the~~to ~~Buyer or any of their respective subsidiaries or affiliates. Moreover~~time, ~~information~~ ~~concerning~~ the ~~subject~~“Price ~~matter~~Determination ofDate”), ~~the~~plus ~~representations~~50 ~~and~~basis ~~warranties may~~points ~~change after~~ (the ~~date of the Merger Agreement, which subsequent information may or may not be fully reflected in our public disclosures.~~“Total

~~FORWARD LOOKING STATEMENT; ADDITIONAL INFORMATION AND WHERE TO FIND IT~~2

~~This~~Consideration”). The ~~written~~Total ~~communication contains~~Consideration ~~forward-looking~~includes ~~statements~~a ~~that~~consent payment ~~involve~~of ~~risks~~$30 ~~and~~per ~~uncertainties concerning~~$1,000 ~~Buyer’s~~principal ~~proposed~~amount ~~acquisition~~ of ~~our~~Notes ~~Parent,~~that ~~our~~will ~~Parent’s~~be ~~and~~payable ~~our~~to ~~expected~~holders ~~financial~~who ~~performance,~~validly astender ~~well~~their asNotes ~~our Parent’s~~ and ~~our~~deliver ~~strategic~~consents ~~and operational~~on ~~plans. Actual events~~ or ~~results~~ ~~may~~prior ~~differ~~to ~~materially from those described in this written~~the ~~communication~~Consent ~~due~~Payment toDeadline aand ~~number~~such ofNotes ~~risks~~are ~~and~~accepted ~~uncertainties~~for purchase. ~~The~~Holders ~~potential~~who ~~risks~~validly ~~and~~tender ~~uncertainties include,~~Notes ~~among~~after ~~others,~~ the Consent ~~possibility~~Payment ~~that~~Deadline ~~the~~but ~~transaction~~on ~~will not close~~ or ~~that~~ ~~the~~prior ~~closing~~to ~~may be delayed,~~ the ~~reaction~~Expiration ofTime ~~our~~will ~~customers~~be entitled to receive the ~~transaction~~ ~~and~~“Tender ~~general~~Offer ~~economic conditions. In addition~~Consideration”, ~~please~~which ~~refer~~is equal to the Total ~~documents~~Consideration ~~that~~less ~~we file with~~ the ~~SEC~~consent ~~on Forms 10-K, 10-Q and 8-K~~payment. ~~Our~~ ~~filings~~In ~~identify~~either ~~and~~case, ~~address~~tendering ~~other~~holders ~~important~~will ~~factors~~receive ~~that~~accrued ~~could~~and ~~cause our~~unpaid ~~financial~~interest ~~and operational results to differ materially~~ from ~~those contained in~~ the ~~forward-looking~~most ~~statements~~recent ~~set~~payment ~~forth in this written communication. Copies~~ of ~~these~~semi-annual ~~filings~~interest ~~may~~preceding ~~also be obtained~~the byapplicable ~~accessing~~payment ~~our~~date ~~website~~up ~~(www.pqcorp.com)~~to, orbut ~~the SEC’s website (www.sec.gov). We do~~ not ~~undertake~~including, ~~any obligation to update any of~~ the ~~forward-looking~~applicable ~~statements~~payment ~~after the~~ date ~~of this press release to conform to actual results~~.

WeThe payment ~~intend~~date ~~that~~will ~~all forward-looking~~be ~~statements~~the ~~made~~“Early ~~will~~Payment beDate” ~~subject~~or tothe ~~safe~~“Final ~~harbor~~Payment ~~protection~~Date.” ofThe ~~the~~Early ~~federal~~Payment ~~securities~~Date ~~laws~~is ~~pursuant~~expected to ~~Section~~follow ~~27A~~promptly of the ~~Securities~~consummation ~~Act~~ of the ~~1933~~Merger and ~~Section~~the ~~21E~~Final ofPayment ~~the~~Date ~~Securities~~is ~~Exchange~~expected ~~Act~~to offollow ~~1934~~promptly the Expiration Time.

~~Item~~In connection 9with the Offer, the Company is soliciting the consents of holders of the Notes to certain proposed amendments to the indenture governing the Notes.01 The ~~Financial~~primary ~~Statements~~purpose of the solicitation and ~~Exhibits~~proposed amendments is to eliminate substantially all of the restrictive covenants and certain events of default from the indenture. Adoption of the proposed amendments requires the consent of the holders of a majority of the aggregate principal amount of the Notes outstanding. Holders who tender their Notes are required to consent to the proposed amendments and holders may not tender their Notes without also delivering consents or deliver consents without also tendering their Notes. This press release does not constitute a notice of redemption under the optional redemption provision of the indenture governing the Notes.

The Offer is conditioned upon the satisfaction of certain conditions, including: (di) ~~Exhibits~~the consummation of the Merger, (ii) the receipt of the requisite consents and the execution of the supplemental indenture containing the proposed amendments described in the Offer to Purchase and (iii) certain other customary conditions described in the Offer to Purchase.

~~2.1 Agreement~~Tendered ~~and~~Notes ~~Plan~~may ~~of Merger, dated~~be ~~May~~withdrawn ~~31, 2007, by~~ and ~~among~~consents ~~Niagara~~may ~~Holdings,~~be ~~Inc.,~~revoked ~~CPQ~~at ~~Holdings~~any ~~LLC,~~time ~~CPQ Acquisition~~prior ~~Corporation~~to ~~and,~~the ~~J.P.~~Consent ~~Morgan Partners (BHCA)~~Payment Deadline, ~~L.P.,~~but ~~solely~~not ~~in its capacity as seller representative~~thereafter.

~~SIGNATURE~~Requests for documents may be directed to Global Bondholder Services Corporation, the Information Agent, at (212) 430-3774 or (866) 470-3800.

~~Pursuant to the requirements~~UBS ~~of the~~ Securities ~~Exchange~~LLC ~~Act~~will ofact ~~1934,~~as ~~the~~Dealer ~~registrant~~Manager ~~has~~for ~~duly~~the ~~caused~~Offer. ~~this~~Questions regarding ~~report~~the toOffer may be ~~signed~~directed onto ~~its~~UBS ~~behalf~~Securities byLLC ~~the~~at ~~undersigned~~888-722-9555 ~~hereunto~~ext. ~~duly authorized~~4210.

	PQ Corporation
Date: June 4, 2007	By:	/s/ James P. Cox
		Name:	James P. Cox
		Title:	Chief Financial Officer, Treasurer and Vice President

This news release is neither an offer to purchase nor a solicitation of an offer to sell the Notes. The Offer is being made only by reference to the Offer to Purchase and related Letter of Transmittal and Consent dated June 26, 2007.

~~EXHIBIT~~PQ Corporation is a leading producer of specialty ~~INDEX~~inorganic chemicals, catalysts and engineered glass materials. The Company conducts operations through three principal businesses: the Performance Chemicals division, which develops, manufactures and distributes sodium silicate and related high performance silicate-based specialty chemicals, the Catalysts division, which manufactures high performance catalytic zeolites and zeolite-based catalysts and polyolefin

Exhibit No.		Description
2.1		Agreement and Plan of Merger, dated May 31, 2007, by and among Niagara Holdings, Inc., CPQ Holdings LLC, CPQ Acquisition Corporation and, J.P. Morgan Partners (BHCA), L.P., solely in its capacity as seller representative.

catalysts, and the Potters division, which manufactures highly engineered solid and hollow glass spheres used in highway safety and other specialty applications. The Company’s products are used in a variety of predominantly niche applications in a diverse range of industrial, consumer and municipal end-markets. The Company operates 60 manufacturing sites in 19 countries on five continents and has one of the most comprehensive global manufacturing and distribution networks serving customers in the Company’s end-markets.

Safe Harbor for Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the federal securities laws relating to the Offer and the Merger. These forward-looking statements generally can be identified by the context of the statement or the use of words such as the Company or its management “believe,” “anticipate,” “intend,” “expect,” “plan,” or words of similar meaning. These statements are based upon management’s current expectations and beliefs and are subject to certain risks and uncertainties that could cause actual results to differ materially from those described in the forward-looking statements. These risks and uncertainties include market conditions and other factors beyond the Company’s control and the risk factors and other cautionary statements discussed in the Company’s filings with the United States Securities and Exchange Commission.

ITEM 9.01 FINANCIAL STATEMENTS AND EXHIBITS.

(d) Exhibits.

10.1 Third Amendment to Credit Agreement, dated as of June 25, 2007, among PQ Corporation, Niagara

Holdings, Inc. and the lenders party thereto.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	PQ Corporation

Date: June 26, 2007	By:	/s/ James P. Cox
		Name:	James P. Cox
		Title:	Chief Financial Officer, Treasurer and Vice President

EXHIBIT INDEX

EXHIBIT NO.		DESCRIPTION

10.1		Third Amendment to Credit Agreement, dated as of June 25, 2007, among PQ Corporation, Niagara Holdings, Inc. and the lenders party thereto.

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