1 EXHIBIT 10.6 THE PIONEER GROUP, INC. CREDIT AGREEMENT AMENDMENT NO. 4 This Agreement, dated as of April 21, 1998, is among The Pioneer Group, Inc., a Delaware corporation (the "Company"), certain of its subsidiaries listed on the signature pages hereto, the Lenders (as defined in the Credit Agreement referenced below) and BankBoston, N.A., f/k/a The First National Bank of Boston, as agent (the "Agent") for itself and the other Lenders. The parties agree as follows: 1. REFERENCE TO CREDIT AGREEMENT; DEFINITIONS. Reference is made to the Credit Agreement dated as of June 6, 1996, among the Company, certain of its subsidiaries, the Lenders and the Agent (as amended, modified and in effect prior to giving effect to this Agreement, the "Credit Agreement"). Terms defined in the Credit Agreement as amended hereby (the "Amended Credit Agreement") and not otherwise defined herein are used herein with the meanings so defined. Except as the context otherwise explicitly requires, the capitalized terms "Section" and "Exhibit" refer to sections hereof and exhibits hereto. 2. AMENDMENT TO CREDIT AGREEMENT. Subject to all of the terms and conditions hereof and in reliance upon the representations and warranties set forth in Section 3, Section 1.9 of the Credit Agreement is amended to read in its entirety as follows: "1.9. "B SHARE CONVERSION DATE" means the earlier of July 21, 1998 or such later date as determined in accordance with Section 2.2.3." 3. REPRESENTATIONS AND WARRANTIES. In order to induce the Lenders to enter into this Agreement, the Company represents and warrants to each of the Lenders that: 3.1. NO DEFAULT. Immediately before and after giving effect to the amendments set forth in Section 2, no Default will exist. 3.2. INCORPORATION OF REPRESENTATIONS AND WARRANTIES. The representations and warranties set forth in Section 8 of the Credit Agreement are true and correct on the date hereof as if originally made on and as of the date hereof (except to the extent any representation or warranty refers to a specific earlier date). 4. GENERAL. The Amended Credit Agreement and all of the other Credit Documents are each confirmed as being in full force and effect. This Agreement, the Amended Credit Agreement and the other Credit Documents referred to herein or therein constitute the entire understanding of the parties with respect to the subject matter hereof and thereof and supersede all prior and current understandings and agreements, whether written or oral, with respect to such subject matter. The invalidity or unenforceability of any provision hereof shall not affect the validity or enforceability of any other term or 2 provision hereof. The headings in this Agreement are for convenience of reference only and shall not alter, limit or otherwise affect the meaning hereof. Each of this Agreement and the Amended Credit Agreement is a Credit Document and may be executed in any number of counterparts, which together shall constitute one instrument, and shall bind and inure to the benefit of the parties and their respective successors and assigns, including as such successor and assigns all holders of any Note. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS (OTHER THAN THE CONFLICT OF LAWS RULES) OF THE COMMONWEALTH OF MASSACHUSETTS. 2 3 Each of the undersigned has caused this Agreement to be executed and delivered by its duly authorized officer as an agreement under seal as of the date first above written. THE PIONEER GROUP, INC. By: /s/ William H. Keough --------------------------------------------- Title: Senior Vice President, Chief Financial Officer and Treasurer 60 State Street Boston, Massachusetts 02109-1820 PIONEERING MANAGEMENT CORPORATION By: /s/ William H. Keough --------------------------------------------- Title: Senior Vice President, Chief Financial Officer and Treasurer PIONEER MANAGEMENT (IRELAND) LTD. By: /s/ John F. Cogan, Jr. --------------------------------------------- Title: Chairman and President of The Pioneer Group, Inc. 60 State Street Boston, Massachusetts 02109-1820 PIONEER FUNDS DISTRIBUTOR, INC. By: /s/ William H. Keough --------------------------------------------- Title: Senior Vice President, Chief Financial Officer and Treasurer 60 State Street Boston, Massachusetts 02109-1820 PIONEERING SERVICES CORP. By: /s/ William H. Keough --------------------------------------------- Title: Senior Vice President, Chief Financial Officer and Treasurer 60 State Street Boston, Massachusetts 02109-1820 3 4 BANKBOSTON, N.A. By: /s/ Karen A. Gallagher -------------------------------- Title: Vice President Financial Institutions Division 100 Federal Street - 15th Floor Boston, Massachusetts 02110 Telecopy: (617) 434-1537 Telex: 940581 THE BANK OF NEW YORK By: /s/ David C. Britton -------------------------------- Title: Vice President One Wall Street, OWS-1 Securities Industry Division New York, New York 10286 Telecopy: (212) 809-9575 Telex: SOCIETE GENERALE By: /s/ Woody Littlefield -------------------------------- Title: Vice President 1221 Avenue of the Americas New York, New York 10020 Telecopy: (212) 278-7153 4 5 STATE STREET BANK & TRUST COMPANY By: /s/ Michael St. Jean -------------------------------- Title: Vice President 225 Franklin Street, 8th Floor Asset-Based Finance Boston, Massachusetts 02110 Telecopy: (617) 338-4041 BANQUE NATIONALE DE PARIS By: /s/ Laurent Vanderzyppe /s/ William Shaheen -------------------------------------------- Title: Vice President Vice President 499 Park Avenue, 2nd Floor New York, New York 10022 Telecopy: (212)) 415-9707 MELLON BANK, N.A. By: /s/ Susan M. Whitewood -------------------------------- Title: Vice President One Mellon Bank Center Mail Code: 1510370 Pittsburgh, Pennsylvania 15258 Telecopy: (412) 234-8087 5