-----BEGIN PRIVACY-ENHANCED MESSAGE----- Proc-Type: 2001,MIC-CLEAR Originator-Name: webmaster@www.sec.gov Originator-Key-Asymmetric: MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB MIC-Info: RSA-MD5,RSA, H0xWJwyWm/SlYAY311Y22MbPABsd9a5ZqEI15qPEoYsXg4K6tkDi+sBEMajftTlG AImd4Fu2F3UwCCCiskR1ug== 0000950156-96-000584.txt : 19960712 0000950156-96-000584.hdr.sgml : 19960712 ACCESSION NUMBER: 0000950156-96-000584 CONFORMED SUBMISSION TYPE: SC 13G PUBLIC DOCUMENT COUNT: 1 FILED AS OF DATE: 19960711 SROS: NONE SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: NATURAL MICROSYSTEMS CORP CENTRAL INDEX KEY: 0000915866 STANDARD INDUSTRIAL CLASSIFICATION: TELEPHONE & TELEGRAPH APPARATUS [3661] IRS NUMBER: 042814586 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13G SEC ACT: 1934 Act SEC FILE NUMBER: 005-43813 FILM NUMBER: 96593362 BUSINESS ADDRESS: STREET 1: 8 ERIE DR CITY: NATICK STATE: MA ZIP: 01760 BUSINESS PHONE: 5086501300 MAIL ADDRESS: STREET 1: 8 ERIE DR CITY: NATICK STATE: MA ZIP: 01760 FILED BY: COMPANY DATA: COMPANY CONFORMED NAME: KEYSTONE INVESTMENT MANAGEMENT CO CENTRAL INDEX KEY: 0000907244 STANDARD INDUSTRIAL CLASSIFICATION: INVESTMENT ADVICE [6282] IRS NUMBER: 041504645 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13G BUSINESS ADDRESS: STREET 1: 200 BERKELEY ST CITY: BOSTON STATE: MA ZIP: 02116 BUSINESS PHONE: 6173383200 MAIL ADDRESS: STREET 1: 200 BERKELEY ST CITY: BOSTON STATE: MA ZIP: 02116 FORMER COMPANY: FORMER CONFORMED NAME: KEYSTONE CUSTODIAN FUNDS INC /DE/ DATE OF NAME CHANGE: 19930617 SC 13G 1 NATURAL MICROSYSTEMS CORP. OMB APPROVAL UNITED STATES OMB Number. 3235-0145 SECURITIES AND EXCHANGE COMMISSION Expires: August 31, 1991 WASHINGTON, D.C. 20549 Estimated average burden hours per response 14.90 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 (AMENDMENT NO. )* Natural Microsystems Corp. -------------------------- (Name of Issuer) Common Stock ------------ (Title of Class of Securities) 63888210 -------- Check the following box if a fee is being paid with the statement [X]. (A fee is not required only if the filing person: (1) has a previous statement on file reporting beneficial ownership of more than five percent of the class of securities described in Item 1; and (2) has filed no amendment subsequent thereto reporting beneficial ownership of five percent or less of such class.) (See Rule 13d-7). *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). CUSIP No. 63888210 13G PAGE 2 OF 13 PAGES -------- 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Keystone Investment Management Company I.R.S. #04-1504645 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* a [X] b [ ] 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware 5. SOLE VOTING POWER 479,834 Shares, Common Stock 6. SHARED VOTING POWER None 7. SOLE DISPOSITION POWER 479,834 Shares, Common Stock 8. SHARED DISPOSITIVE POWER None 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 479,834 Shares, Common Stock 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 10.44% 12. TYPE OF REPORTING PERSON* CO *SEE INSTRUCTION BEFORE FILLING OUT! CUSIP No. 63888210 13G PAGE 3 OF 13 PAGES -------- 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Keystone Small Company Growth Fund (S-4) I.R.S. #04-2394427 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* a [X] b [ ] 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION Pennsylvania 5. SOLE VOTING POWER 200,000 Shares, Common Stock 6. SHARED VOTING POWER None 7. SOLE DISPOSITION POWER 200,000 Shares, Common Stock 8. SHARED DISPOSITIVE POWER None 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 200,000 Shares, Common Stock 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 4.35% 12. TYPE OF REPORTING PERSON* IV *SEE INSTRUCTION BEFORE FILLING OUT! CUSIP No. 63888210 13G PAGE 4 OF 13 PAGES -------- 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Keystone Global Opportunities Fund I.R.S. #04-6584551 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* a [X] b [ ] 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION Massachusetts 5. SOLE VOTING POWER 65,000 Shares, Common Stock 6. SHARED VOTING POWER None 7. SOLE DISPOSITION POWER 65,000 Shares, Common Stock 8. SHARED DISPOSITIVE POWER None 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 65,000 Shares, Common Stock 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 1.4% 12. TYPE OF REPORTING PERSON* IV *SEE INSTRUCTION BEFORE FILLING OUT! CUSIP No. 63888210 13G PAGE 5 OF 13 PAGES -------- 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Keystone Small Company Growth Fund II I.R.S. #04-3297392 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* a [X] b [ ] 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION Massachusetts 5. SOLE VOTING POWER 12,100 Shares, Common Stock 6. SHARED VOTING POWER None 7. SOLE DISPOSITION POWER 12,100 Shares, Common Stock 8. SHARED DISPOSITIVE POWER None 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 12,100 Shares, Common Stock 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.26% 12. TYPE OF REPORTING PERSON* IV *SEE INSTRUCTION BEFORE FILLING OUT! CUSIP No. 63888210 13G PAGE 6 OF 13 PAGES -------- 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Keystone Institutional Trust - Keystone Institutional Small Capitalization Growth Fund I.R.S. #04-3295682 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* a [X] b [ ] 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION Massachusetts 5. SOLE VOTING POWER 1,700 Shares, Common Stock 6. SHARED VOTING POWER None 7. SOLE DISPOSITION POWER 1,700 Shares, Common Stock 8. SHARED DISPOSITIVE POWER None 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,700 Shares, Common Stock 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.04% 12. TYPE OF REPORTING PERSON* IV *SEE INSTRUCTION BEFORE FILLING OUT! CUSIP No. 63888210 13G PAGE 7 OF 13 PAGES -------- 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Keystone Investment Management Company I.R.S. #04-1504645 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* a [X] b [ ] 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware 5. SOLE VOTING POWER 153,434 Shares, Common Stock 6. SHARED VOTING POWER None 7. SOLE DISPOSITION POWER 153,434 Shares, Common Stock 8. SHARED DISPOSITIVE POWER None 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 153,434 Shares, Common Stock 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 3.34% 12. TYPE OF REPORTING PERSON* IA (for the Merrill Lynch Consults Portfolio)** ** Total above represents aggregate holdings for approximately 2500 accounts, managed by Keystone Investment Management Company, none of which individually owns more than .05% of the securities. *SEE INSTRUCTION BEFORE FILLING OUT! CUSIP No. 63888210 13G PAGE 8 OF 13 PAGES -------- 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Keystone Investment Management Company I.R.S. #04-1504645 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* a [X] b [ ] 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware 5. SOLE VOTING POWER 47,600 Shares, Common Stock 6. SHARED VOTING POWER None 7. SOLE DISPOSITION POWER 47,600 Shares, Common Stock 8. SHARED DISPOSITIVE POWER None 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 47,600 Shares, Common Stock 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 1.04% 12. TYPE OF REPORTING PERSON* IA (for Concord Hospital Small Capital Qualified Account (2,400 Shares), Concord Hospital Small Capital Non-Qualified Account (3,700), General Retirement of Detroit (23,000), Employees Retirement System Puerto Rico Electric Power (17,000 Shares), George S. Bissell Charitable Remainder Trust (1,500)) *SEE INSTRUCTION BEFORE FILLING OUT! PAGE 9 OF 13 PAGES Item 1(a). Name of Issuer: Natural Microsystems Corp. Item 1(b). Address of Issuer's Principal Executive Offices: 8 Erie Drive Natick, MA 01760 Item 2(a). Name of Person Filing: Keystone Investment Management Company Item 2(b). Address of Principal Business Office, or, if none, residence: 200 Berkeley Street Boston, MA 02116 Item 2(c). Place of organization: Delaware Item 2(d). Title of Class of Securities: Common Stock Item 2(e). CUSIP Number: 63888210 Item 3. If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b), check whether the person filing is a: (a) [ ] Broker or Dealer registered under Section 15 of the Act (b) [ ] Bank as defined in Section 3(a)(6) of the Act (c) [ ] Insurance Company as defined in Section 3(a)(19) of the Act (d) [ ] Investment Company registered under Section 8 of the Investment Company Act (e) [ ] Investment Company registered under Section 203 of the Investment Advisers Act of 1940 (f) [ ] Employee Benefit Plan, Pension Fund which is subject to the provisions of the Employee Retirement Income Security Act of 1974 or Endowment Fund; see Section 240.13d-1(b)(1)(ii)(F) (g) [ ] Parent Holding Company, in accordance with Section 240.13d-1(b)(ii)(G) (Note: See Item 7) (h) [X] Group, in accordance with Section 240.13d-1(b) (1)(ii)(H) PAGE 10 OF 13 PAGES Item 4. Ownership: If the percent of the class owned, as of December 31 of the year covered by the statement, or as of the last day of any month described in Rule 13d-1(b)(2), if applicable, exceeds five percent, provide the following information as of that date and identify those shares which there is a right to acquire. (a) Amount Beneficially Owned: 479,834 (b) Percent of Class: 10.44% (c) Number of shares as to which such person has: (I) sole power to vote or to direct the vote: 479,834 (ii) shared power to vote or to direct the vote: None (iii) sole power to dispose or to direct the disposition of: 479,834 (iv) shared power to dispose of or to direct the disposition of: None Item 5. Ownership of Five Percent or Less of a Class: If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [ ]. Item 6. Ownership of More than Five Percent on Behalf of Another Person: N/A Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company: N/A Item 8. Identification and Classification of Members of the Group: See Exhibit A Item 9. Notice of Dissolution of Group: N/A PAGE 11 OF 13 PAGES Item 10. Certification: The following certificate shall be included if the statement is filed pursuant to Rule 13-1(b): By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purposes of effect. After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. KEYSTONE INVESTMENT MANAGEMENT COMPANY -------------------------------------- (Name of Entity) By /s/ Albert H. Elfner, III ------------------------- Title: Chairman Dated: July 1, 1996 PAGE 12 OF 13 PAGES EXHIBIT A MEMBERS OF THE GROUP (Item 8) Item 3 Identity Classification 1. Keystone Investment Management Company (e) Investment Adviser 2. Keystone Small Company Growth Fund (S-4) (d) Investment Company 3. Keystone Global Oppportunities Fund (d) Investment Company 4. Keystone Small Company Growth Fund II (d) Investment Company 5. Keystone Institutional Trust - Keystone Institutional Small Capitalization Fund (d) Investment Company 6. Keystone Investment Management Company (e) Investment Adviser 7. Keystone Investment Management Company (e) Investment Adviser PAGE 13 OF 13 PAGES EXHIBIT B The undersigned all hereby agree in writing that Schedule 13G, filed with the Securities and Exchange Commission by Keystone Investment Management Company, and containing information required by Schedule 13G with respect to beneficial ownership of the same shares of the Common Stock of Natural Microsystems Corp. is jointly filed on behalf of each of Keystone Investment Management Company, Keystone Small Company Growth Fund (S-4), Keystone Global Opportunities Fund, Keystone Small Company Growth Fund II, Keystone Institutional Trust - Keystone Institutional Small Capitalization Fund, Keystone Investment Management Company for Merrill Lynch Wrap Account, Keystone Investment Management Company for Concord Hospital Small Capital Qualified Account, Concord Hospital Small Capital Non-Qualified Account, General Retirement of Detroit, Employees Retirement System Puerto Rico Electric Power, George S. Bissell Charitable Remainder Trust. KEYSTONE INVESTMENT MANAGEMENT COMPANY By: /s/ Albert H. Elfner, III --------------------------- Title: Chairman KEYSTONE SMALL COMPANY GROWTH FUND (S-4) By: /s/ Albert H. Elfner, III --------------------------- Title: Chairman KEYSTONE GLOBAL OPPORTUNITIES FUND By: /s/ Albert H. Elfner, III --------------------------- Title: Chairman KEYSTONE SMALL COMPANY GROWTH FUND II By: /s/ Albert H. Elfner, III --------------------------- Title: Chairman KEYSTONE INSTITUTIONAL TRUST - KEYSTONE INSTITUTIONAL SMALL CAPITALIZATION FUND By: /s/ Albert H. Elfner, III --------------------------- Title: Chairman KEYSTONE INVESTMENT MANAGEMENT COMPANY for Merrill Lynch Wrap Account By: /s/ Albert H. Elfner, III --------------------------- Title: Chairman KEYSTONE INVESTMENT MANAGEMENT COMPANY for Concord Hospital Small Capital Qualified Account, Concord Hospital Small Capital Non-Qualified Account, General Retirement of Detroit, Employees Retirement System Puerto Rico Electric Power, George S. Bissell Charitable Remainder Trust By: /s/ Albert H. Elfner, III ------------------------- Title: Chairman -----END PRIVACY-ENHANCED MESSAGE-----