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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. 2)
Sonus, Corp.
(Name of Issuer)
Common Stock
(Title of Class of Securities)
835691106
(CUSIP Number)
March 1, 1999
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:
/___/ Rule 13d-1(b)
/_x_/ Rule 13d-1(c)
/___/ Rule 13d-1(d)
* 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 disclosures provided in a prior cover page.
The information required on 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).
Potential persons who are to respond to the collection of information
contained in this form are not required to respond unless the form displays
a currently valid OMB control number.
SEC 1745 (3-98) Page 1 of 11
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CUSIP No. 835691106 13G Page 2 of 11 Pages
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1 NAME OF REPORTING PERSONS
IRS IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
RS Investment Management Co. LLC
- ----------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)
(a)/ /
(b)/ /
- ----------------------------------------------------------------
3 SEC USE ONLY
- ----------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
- ----------------------------------------------------------------
NUMBER OF 5 SOLE VOTING POWER
SHARES -0-
BENEFICIALLY ---------------------------------------
OWNED BY 6 SHARED VOTING POWER
EACH 809,800
REPORTING ---------------------------------------
PERSON 7 SOLE DISPOSITIVE POWER
WITH -0-
---------------------------------------
8 SHARED DISPOSITIVE POWER
809,800
- ----------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
809,800
- ----------------------------------------------------------------
10 CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (See
Instructions)
- ----------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
13.2%
- ----------------------------------------------------------------
12 TYPE OF REPORTING PERSON (See Instructions)
OO, HC
- ----------------------------------------------------------------
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CUSIP No. 835691106 13G Page 3 of 11 Pages
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1 NAME OF REPORTING PERSONS
IRS IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
RS Investment Management, L.P.
- ----------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)
(a)/ /
(b)/ /
- ----------------------------------------------------------------
3 SEC USE ONLY
- ----------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
California
- ----------------------------------------------------------------
NUMBER OF 5 SOLE VOTING POWER
SHARES -0-
BENEFICIALLY ---------------------------------------
OWNED BY 6 SHARED VOTING POWER
EACH 809,800
REPORTING ---------------------------------------
PERSON 7 SOLE DISPOSITIVE POWER
WITH -0-
---------------------------------------
8 SHARED DISPOSITIVE POWER
809,800
- ----------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
809,800
- ----------------------------------------------------------------
10 CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (See
Instructions)
- ----------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
13.2%
- ----------------------------------------------------------------
12 TYPE OF REPORTING PERSON (See Instructions)
PN, IA
- ----------------------------------------------------------------
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CUSIP No. 835691106 13G Page 4 of 11 Pages
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1 NAME OF REPORTING PERSONS
IRS IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
RS Value Group LLC
- ----------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)
(a)/ /
(b)/ /
- ----------------------------------------------------------------
3 SEC USE ONLY
- ----------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
- ----------------------------------------------------------------
NUMBER OF 5 SOLE VOTING POWER
SHARES -0-
BENEFICIALLY ---------------------------------------
OWNED BY 6 SHARED VOTING POWER
EACH 802,300
REPORTING ---------------------------------------
PERSON 7 SOLE DISPOSITIVE POWER
WITH -0-
---------------------------------------
8 SHARED DISPOSITIVE POWER
802,300
- ----------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
802,300
- ----------------------------------------------------------------
10 CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (See
Instructions)
- ----------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
13.1%
- ----------------------------------------------------------------
12 TYPE OF REPORTING PERSON (See Instructions)
OO
- ----------------------------------------------------------------
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CUSIP No. 835691106 13G Page 5 of 11 Pages
- ----------------------------------------------------------------
1 NAME OF REPORTING PERSONS
IRS IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
The RS Orphan Fund, L.P.
- ----------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)
(a)/ /
(b)/ /
- ----------------------------------------------------------------
3 SEC USE ONLY
- ----------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
California
- ----------------------------------------------------------------
NUMBER OF 5 SOLE VOTING POWER
SHARES -0-
BENEFICIALLY ---------------------------------------
OWNED BY 6 SHARED VOTING POWER
EACH 630,300
REPORTING ---------------------------------------
PERSON 7 SOLE DISPOSITIVE POWER
WITH -0-
---------------------------------------
8 SHARED DISPOSITIVE POWER
630,300
- ----------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
630,300
- ----------------------------------------------------------------
10 CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (See
Instructions)
- ----------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
10.3%
- ----------------------------------------------------------------
12 TYPE OF REPORTING PERSON (See Instructions)
PN
- ----------------------------------------------------------------
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CUSIP No. 835691106 13G Page 6 of 11 Pages
ITEM 1.
(a) The name of the issuer is Sonus Corp. (the "Issuer").
(b) The principal executive office of the Issuer is located at 111 SW
5th Avenue, Suite 2390, Portland, OR 97204.
ITEM 2.
(a-c) See Annex I for information on the persons filing this statement
(collectively, the "Filers").
(d) This statement relates to shares of common stock of the Issuer
(the "Stock").
(e) The CUSIP number of the Stock is 835691106.
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CUSIP No. 835691106 13G Page 7 of 11 Pages
ITEM 3. If this statement is filed pursuant to rule 240.13d-1(b) or 240.13d-
2(b) or (c), check whether the person filing is a:
(a) ___ Broker or dealer registered under section 15 of the Act (15
U.S.C. 78o).
(b) ___ Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
(c) ___ Insurance company as defined in section 3(a)(19) of the Act
(15 U.S.C. 78c).
(d) ___ Investment company registered under section 8 of the
Investment Company Act of 1940 (15 U.S.C. 80a-8).
(e) ___ An investment adviser in accordance with 240.13d-
1(b)(1)(ii)(E).
(f) ___ An employee benefit plan or endowment fund in accordance with
240.13d-1(b)(1)(ii)(F).
(g) ___ A parent holding company or control person in accordance with
240.13d-1(b)(1)(ii)(G)
(h) ___ A savings association as defined in section 3(b) of the
Federal Deposit Insurance Act (12 U.S.C. 1813).
(i) ___ A church plan that is excluded from the definition of an
investment company under section 3(c)(14) of the Investment Company Act of
1940 (15 U.S.C. 80a-3).
(j) ___ Group, in accordance with section 240.13d-1(b)(1)(ii)(J)
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CUSIP No. 835691106 13G Page 8 of 10 Pages
ITEM 4. OWNERSHIP
See Items 5-9 and 11 on the cover page for each Filer.
ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS
Not applicable.
ITEM 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON
RS Investment Management, L.P. is a registered investment adviser whose
clients have the right to receive or the power to direct the receipt of
dividends from, or the proceeds from the sale of, the Stock. No client
other than The RS Orphan Fund, L.P. owns greater than 5% of the Stock.
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CUSIP No. 835691106 13G Page 9 of 11 Pages
ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY
Not applicable.
ITEM 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP
See Annex I
ITEM 9. NOTICE OF DISSOLUTION OF GROUP
Not applicable.
ITEM 10. CERTIFICATION
By signing below I certify that, to the best of my knowledge and belief, the
securities referred to above were not acquired and are not held for the
purpose of or with the effect of changing or influencing the control of the
issuer of the securities and were not acquired and are not held in
connection with or as a participant in any transaction having that purpose
or effect.
SIGNATURE
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.
Dated: July 20, 1999
RS INVESTMENT MANAGEMENT CO. LLC
By: /s/ G. Randall Hecht
G. Randall Hecht
Chief Executive Officer
RS INVESTMENT MANAGEMENT, L.P.
By: /s/ G. Randall Hecht
G. Randall Hecht
Chief Executive Officer
RS VALUE GROUP LLC
By: RS Investment Management, L.P.
Manager
By: /s/ G. Randall Hecht
G. Randall Hecht
Chief Executive Officer
THE RS ORPHAN FUND, L.P.
By: RS Value Group LLC
General Partner
By: RS Investment Management, L.P
Manager
By: /s/ G. Randall Hecht
G. Randall Hecht
Chief Executive Officer
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CUSIP No. 835691106 13G Page 10 of 11 Pages
EXHIBIT A
JOINT FILING AGREEMENT
The undersigned hereby agree that they are filing this statement jointly
pursuant to Rule 13d-1(f)(1). Each of them is responsible for the timely
filing of the Schedule 13G and any amendments thereto, and for the
completeness and accuracy of the information concerning such person
contained therein; but none of them is responsible for the completeness or
accuracy of the information concerning the other persons making the filing,
unless such person knows or has reason to believe that such information is
accurate.
Dated: July 20, 1999
RS INVESTMENT MANAGEMENT CO. LLC
By: /s/ G. Randall Hecht
G. Randall Hecht
Chief Executive Officer
RS INVESTMENT MANAGEMENT, L.P.
By: /s/ G. Randall Hecht
G. Randall Hecht
Chief Executive Officer
RS VALUE GROUP LLC
By: RS Investment Management, L.P.
Manager
By: /s/ G. Randall Hecht
G. Randall Hecht
Chief Executive Officer
THE RS ORPHAN FUND, L.P.
By: RS Value Group LLC
General Partner
By: RS Investment Management, L.P
Manager.
By: /s/ G. Randall Hecht
G. Randall Hecht
Chief Executive Officer
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CUSIP No. 835691106 13G Page 11 of 11 Pages
Annex I
The filers are:
I. (a) RS Investment Management Co. LLC, a Delaware Limited
Liability Company, is the General Partner of RS Investment
Management, L.P.
(b) holding company
II. (a) RS Investment Management, L.P., a California Limited
Partnership, is the Manager of RS Value Group LLC.
(b) registered investment adviser
III. (a) RS Value Group LLC, a Delaware Limited Liability Company, is the
General Partner of The RS Orphan Fund, L.P.
(b) holding company
IV. (a) The RS Orphan Fund, L.P. is a California Limited Partnership.
(b) investment partnership
The principal office and principal place of business of the filers is 388
Market Street, Suite 200, San Francisco, CA 94111:
