THE CORPORATE LIBRARY

Related Party Transactions and Outside Related Director Information

Koppers Holdings Inc. (KOP)

2/2/2006 424B1 Information

Relationship with Legal Counsel

Schnader Harrison Segal & Lewis LLP provided counsel to us during 2005 and 2004. Clayton A. Sweeney, a shareholder and director, is also counsel to Schnader Harrison Segal & Lewis LLP. During 2005 and 2004, we paid a total of $0.1 million and $0.2 million, respectively, in legal fees to this firm. Additionally, from 2002 to 2005 we redeemed from Mr. Sweeney a total of 290,385 shares for a total redemption amount of approximately $1.4 million. The prices at which we redeemed Mr. Sweeney’s shares were based on fair value less dividends paid. The board of directors (with Mr. Sweeney abstaining) determined the fair value of our stock based on annual valuations performed by a third party valuation firm. Beginning with the year 2002, the fair value was reduced dollar-for-dollar by the amount of any dividends paid between valuation periods.

Consulting Agreements

Consulting Agreement with Robert Cizik. In 1999, Koppers Inc. entered into a consulting agreement, or the Consulting Agreement, with Robert Cizik in which it has paid a fee of $12,500 per month to Mr. Cizik for consulting services. Mr. Cizik has advised our board of directors and our management with respect to, and has provided leadership and oversight in connection with, the establishment and execution of strategic and tactical business plans, operating and management policies and acquisition strategies and opportunities to help position us for the future. He has also provided other advice, services and consultations at the request of our board of directors or us from time to time. The Consulting Agreement includes a provision which allowed Mr. Cizik to purchase 79,598 shares of common stock for $4.27 per share, which purchase was made in October 1999 when the fair value per share was $4.33. Additionally, the agreement provides for a $0.6 million interest-free loan from Koppers Inc. for the purchase of 140,467 shares of restricted common stock at a price of $4.27 per share. Mr. Cizik purchased these shares in October 1999 by signing a promissory note to Koppers Inc. for $0.6 million. The note, which is 70% collateralized by the value of the related shares and 30% by Mr. Cizik’s personal assets, is due in 2009, or immediately in the event Mr. Cizik is no longer Non-Executive Chairman of our board of directors. The shares were initially restricted, with a vesting period of five years; at December 31, 2003, all the shares were vested. Mr. Cizik has the right to require us to redeem the 140,467 shares at any time at the lower of his cost or current fair value; however, the disposition or transfer of the shares requires the related loan to be repaid immediately.

On December 7, 2005, the board of directors of Koppers Inc. (with Mr. Cizik abstaining) voted to authorize the termination of the Consulting Agreement and to increase the annual compensation of the Non-Executive Chairman by $30,000 per year effective January 1, 2006. On December 23, 2005, Koppers Inc. and Mr. Cizik executed an agreement to terminate the Consulting Agreement, effective January 1, 2006. In connection with such termination, we agreed to pay Mr. Cizik the sum of $600,000 on December 31, 2005 and Mr. Cizik agreed to continue to serve as our director for at least two years.

Mr. Cizik will also remain as Non-Executive Chairman of Koppers Inc., but he will receive no additional compensation for such services. The termination of the Consulting Agreement will not affect the terms of Mr. Cizik’s interest-free loan or his stock ownership.

Advisory Services Agreement with Saratoga Partners III, L.P. We had an advisory and consulting agreement with of Saratoga Partners III, L.P. pursuant to which Koppers Inc. paid a management fee of $150,000 per quarter to an affiliate of Saratoga Partners III, L.P. in lieu of Director’s fees to Mr. Oberbeck. Prior to the termination of the advisory services agreement, affiliates of Saratoga Partners III, L.P. provided us with financial advisory services in connection with significant business transactions, including, but not limited to: (i) identification, negotiation and analysis of acquisitions and dispositions by us or our subsidiaries; (ii) negotiations and analysis of financing alternatives, including in connection with acquisitions, capital expenditures and refinancing of indebtedness; (iii) finance functions, including assistance in financial projections; (iv) human resource functions, including searching and hiring of executives; and (v) such other services as our board of directors and Saratoga Partners III, L.P. shall agree. For such services, we paid affiliates of Saratoga Partners III, L.P. compensation comparable to compensation paid for such services by similarly situated companies. During 2004 and 2003, we paid an affiliate of Saratoga Partners III, L.P. $0.5 million and $1.6 million, respectively, related to advisory services related to refinancing activities. The advisory services agreement was terminated in February 2006 and an affiliate of Saratoga Partners was paid a financial advisory services termination fee of $3.0 million.

Mr. Oberbeck has served as a director of Koppers Inc. since October 1997. Mr. Oberbeck is one of the founders of Saratoga Partners, where he has been a Managing Director since its formation as an independent entity in September 1998. Prior to that time, Mr. Oberbeck was a Managing Director of Warburg Dillon Read Inc. and its predecessor entity Dillon, Read & Co. Inc. from 1995 to September 1998, where he was responsible for the management of the Saratoga Funds, and Managing Director of Castle Harlan, Inc., a corporate buyout firm, where he worked from 1987 to 1995.

Saratoga Partners III, L.P. has informed us that it is an independent New York based investment firm making private equity investments in partnership with management in the business services and manufacturing industries. Saratoga Partners III, L.P. was founded in 1984 as the corporate buyout group of Dillon, Read & Co. Inc. and is an experienced firm, having led buyout investments in 33 companies.

Stockholders’ Agreement

Prior to November 2004, the Company was a party to a stockholders’ agreement. When the common and preferred stock of Koppers Inc. was converted into common and preferred stock of Koppers Holdings Inc. as noted above, the stockholders’ agreement of Koppers Inc. was amended to provide for the transfer of the terms and conditions of the stockholders’ agreement from Koppers Inc. to Koppers Holdings Inc. The management investors were a group of approximately 120 individual stockholders with various ownership interests in the common stock and collectively comprising 100% of the total outstanding shares of the common stock of the Company. Each management investor was an officer, director, or current or former employee of either Koppers or one of its subsidiaries.

The stockholders’ agreement had set forth supermajority voting requirements for the Board of Directors for certain matters, including the issuance of additional stock, mergers, consolidations, acquisitions, significant asset sales, and the incurrence of material indebtedness. Majority owner Saratoga Partners III, L.P. (“Saratoga”) was entitled to nominate a majority of the Board of Directors. Prior to February 27, 2004 the stockholders’ agreement required the Company to redeem shares upon a management investor’s ceasing for any reason to be employed by the Company. On February 27, 2004 the stockholders’ agreement was amended to make the redemption of common stock from such management investors at the option of the Company after the effective date of the amendment.

In 2005, 2004 and 2003 we declared dividends of $3.19, $8.51 and $5.89 per share, respectively, to common and, prior to the conversion of preferred stock into common shares on a 3.9799-for-one basis, $12.68, $33.85 and $23.46 per share, respectively, to preferred shareholders.