AMENDMENT NO. 1, WAIVER AND CONSENT TO REVOLVING CREDIT AGREEMENT

Exhibit 4.4

AMENDMENT NO. 1, WAIVER AND CONSENT TO
REVOLVING CREDIT AGREEMENT

      THIS AMENDMENT NO. 1, WAIVER AND CONSENT TO REVOLVING CREDIT AGREEMENT , dated as of November 10, 2006, (this " Amendment "), among the following:

     (i)  OM GROUP, INC. , a Delaware corporation (herein, together with its successors and assigns the " Borrower ");

     (ii) the financial institutions party hereto as Lenders; and

     (iii)  NATIONAL CITY BANK , as the administrative agent (in such capacity, the " Administrative Agent ") and the collateral agent (in such capacity, the " Collateral Agent ") for the Lenders.

PRELIMINARY STATEMENTS:

      WHEREAS , the Borrower, the Lenders named therein, the Administrative Agent, the Collateral Agent and the other parties thereto entered into the Revolving Credit Agreement, dated as of December 20, 2005 (the " Credit Agreement "); capitalized terms used herein and not otherwise defined herein have the meanings ascribed to such terms in the Credit Agreement.

      WHEREAS , the Borrower has notified the Administrative Agent that the Borrower, directly or indirectly through one or more Subsidiaries, intends to sell (the " Nickel Business Sale ") (i) all of the issued and outstanding shares of common stock, no par value per share, of OMG Kokkola Chemicals Holding BV, a company organized under the laws of The Netherlands (ii) all of the issued and outstanding shares of common stock, par value €1,122.07 (not an exact value) per share, of OMG Harjavalta Nickel Oy, a company organized under the laws of Finland; and (iii) under certain circumstances, 68,966 of the issued and outstanding shares of common stock, par value €0.01 per share, and a debt interest convertible into an additional 104,945 shares of Talvivaaran Kaivososakeyhtiö, a company organized under the laws of Finland (collectively, the " Nickel Business" ). The Nickel Business Sale is not permitted under Section 9.2(d) of the Credit Agreement or any other provision thereof and, accordingly, the Borrower has requested that the Administrative Agent and the Lenders consent to the Nickel Business Sale.

      WHEREAS , the Borrower has requested that the Administrative Agent and the Lenders waive the provisions of Section 4.3(c) of the Credit Agreement that require a reduction in the Total Revolving Commitment as a result of the Borrower’s receipt of Net Cash Proceeds from the Nickel Business Sale.

      WHEREAS , the Borrower has requested that, notwithstanding anything in the Credit Agreement to the contrary, the Nickel Business shall be taken into account when calculating financial covenants prior to the date the Nickel Business is sold and, after the date the Nickel Business is sold, it shall not be taken into account for purposes of such calculations.

      WHEREAS , the parties hereto desire to otherwise amend certain terms of the Credit Agreement, as more fully set forth below.

      NOW, THEREFORE , the parties hereby agree as follows:

          SECTION 1. AMENDMENTS.

           1.1 Effective on the date that the Nickel Business Sale is consummated (the " Nickel Sale Closing Date "), provided that the Amendment Effective Date has occurred, Section 1.1 of the Credit Agreement is hereby amended by amending and restating the definition of Leverage Ration to read in its entirety as follows:

     " Leverage Ratio " means, as of any date of determination, the ratio of (i) Consolidated Net Debt at such time to (ii) Consolidated EBITDA for the Testing Period most recently ended.

           1.2 Effective on the Nickel Sale Closing Date, provided that the Amendment Effective Date has occurred, Section 1.1 of the Credit Agreement is hereby amended by inserting the following new definition in appropriate alphabetic order to read as follows:

     " Consolidated Net Debt " means, as of any date of determination, Consolidated Total Debt minus all cash and Cash Equivalents of the Borrower and its Subsidiaries at such time.

           1.3 Effective on the Nickel Sale Closing Date, provided that the Amendment Effective Date has occurred, Section 1.1 of the Credit Agreement is hereby amended by inserting the following new definition in appropriate alphabetic order to read as follows:

     " Consolidated Net Worth " means, as of any date of determination, all amounts that, in conformity with GAAP, would be included under the caption "total stockholders’ equity" (or any like caption) on a consolidated balance sheet of the Borrower and its Subsidiaries as of such date.

           1.4 Effective on the Nickel Sale Closing Date, provided that the Amendment Effective Date has occurred, Section 1.1 of the Credit Agreement is hereby amended by inserting the following new definition in appropriate alphabetic order to read as follows:

     " First Amendment " means that certain Amendment No. 1, Waiver and Consent to Revolving Credit Agreement dated as of November 10, 2006 by and among the Company, the Lenders party thereto and the Administrative Agent and Collateral Agent.

           1.5 Effective on the Nickel Sale Closing Date, provided that the Amendment Effective Date has occurred, Section 9.7 of the Credit Agreement is hereby amended and restated in its entirety to read as follows:

      9.7. Leverage Ratio . The Borrower will not on the last day of any Testing Period indicated below permit its Leverage Ratio for the Testing Period most recently ended to exceed the ratio specified below:

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           1.6 Effective on the Nickel Sale Closing Date, provided that the Amendment Effective Date has occurred, Section 9.8 of the Credit Agreement is hereby amended and restated in its entirety to read as follows:

      9.8. Minimum Net Worth . The Borrower will not permit its Consolidated Net Worth on the last day of any Testing Period to be less than the sum of (i) the Consolidated Net Worth of the Borrower and its Subsidiaries after giving effect to the Nickel Business Sale (as defined in the First Amendment) as of last day of the month during which the Nickel Sale Closing Date (as defined in the First Amendment) shall have occurred minus $50,000,000 plus (ii) for each fiscal quarter (or portion thereof) ending after the Nickel Sale Closing Date and thereafter, the greater of (x) 75% of Consolidated Net Income for such fiscal quarter (or portion thereof) and (y) zero (0), provided that Consolidated Net Worth shall be calculated without giving effect to the impact of any working capital adjustment under the definitive documents governing the Nickel Business Sale.

           1.7 Effective on the Nickel Sale Closing Date, provided that the Amendment Effective Date has occurred, a new Section 9.15 of the Credit Agreement is hereby inserted in appropriate numerical order and shall read in its entirety as follows:

      9.15. Consolidated Capital Expenditures . The Borrower will not make Consolidated Capital Expenditures in excess of Fifty Million Dollars ($50,000,000) during any Testing Period if the Borrower has Revolving Loans outstanding on the last day of such Testing Period.

           1.8 Effective on the Nickel Sale Closing Date, provided that the Amendment Effective Date has occurred, Section 10.1(c) of the Credit Agreement is hereby amended by inserting the phrase "or 9.15" immediately after the occurrence of "inclusive," therein.

          SECTION 2. CONSENTS AND WAIVERS.

     Effective as of the Amendment Effective Date, the Administrative Agent and the Lenders hereby (a) notwithstanding any provision in the Credit Agreement or the other Credit Documents to the contrary, consent to the consummation of the Nickel Business Sale, (b) waive the

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provisions of Section 4.3(c) of the Credit Agreement that would otherwise require a reduction in the Total Revolving Commitment as a result of the Borrower’s receipt of Net Cash Proceeds from the Nickel Business Sale, and (c) agree with the Borrower that, notwithstanding anything to the contrary in the Credit Agreement, the Nickel Business shall be taken into account when calculating financial covenants prior to the date the Nickel Business is sold and, after the date the Nickel Business is sold, it shall not be taken into account for purposes of such calculations; provided that each of the foregoing limited waivers, consents and agreements is expressly conditioned upon the following: (x) no Default or Event of Default shall exist immediately prior to or, after giving effect to the provisions hereof, immediately after consummation of the Nickel Business Sale, (y) Net Cash Proceeds (exclusive of any working capital adjustments) from the Nickel Business Sale are at least $300,000,000, and (z) the Borrower and its Subsidiaries shall not have liabilities under the indemnification provisions of the definitive agreements governing the Nickel Business Sale in excess of 20% of the total cash transa