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                                                                   EXHIBIT 10.9

December 28, 1999



Mr. Limor Schweitzer

Dear Limor,

          We are pleased to offer you a position with XACCT Technologies, Inc.,
a Delaware corporation (the "Company"), as a Chief Technology Officer starting
on or about January 1, 2000. In this position, you will report to the President
and Chief Executive Officer for the Company, and shall assume and discharge such
responsibilities as are commensurate with a senior position. During the term of
your employment you shall devote your full time, skill and attention to your
duties and responsibilities and shall perform them faithfully, diligently and
competently. In addition, you shall comply with the policies, procedures and
practices of the Company as in effect from time to time.

          You will receive a monthly base salary of $13,750.00 which will be
paid bi-weekly in accordance with the Company's normal payroll procedures; you
will also receive a $16,500 annual bonus contingent upon your achieving specific
performance objectives. To assist you in your relocation, we will pay actual
relocation costs up to $10,000; if charges exceed $10,000 they will be reviewed
on an individual case basis. If you are unable to secure housing prior to your
expected start date, we will provide up to 45 days temporary housing; we will
provide up to 45 days car rental while you arrange for a personal vehicle. When
you have arranged more permanent housing, we will pay for the installation and
continued use of a Pacific Bell DSL line. So that you do not lose touch with
your family in Israel, we will pay for one round-trip visit per year to Israel
for you and your immediate family. After at least one year, at the conclusion of
your assignment in the United States, we will pay for your relocation back to
Israel. In the event you should leave the company prior to completing one year's
service, you will be required to repay the bonus and relocation expenses on a
prorated basis. As a Company employee, you will also be eligible to receive
certain employee benefits including participation in the Company's health
insurance plan and 401K program to the extent of your eligibility under their
terms. You should note that the Company might modify salaries and benefits from
time to time as it deems necessary.

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          You should be aware that your employment with the Company is for no
specified period and constitutes "at-will" employment. As a result, you are free
to resign at any time, for any reason or for no reason. In the event the Company
wishes to conclude its employment relationship with you without cause, we will
provide you with 45 days notice and you will be paid during this time.
Termination with cause will be immediate, with or without notice, and you will
be paid up to the day of your termination. In either case, we will pay for your
relocation back to Israel.

          For purposes of federal immigration laws, you will be required to
provide to the Company documentary evidence of your identity and eligibility for
employment in the United States. Such documentation must be provided to us
within three (3) business days of your date of hire, or our employment
relationship with you may be terminated.

          You agree that, during the term of your employment with the Company,
you will not actively engage in any other employment, occupation, consulting or
other business directly or indirectly related to the business in which the
Company or XACCT Ltd. is now involved or becomes involved during the term of
your employment, nor will you engage in any other activities that conflict with
your obligations to the Company or XACCT Ltd.

          As a Company employee, you will be expected to abide by the Company's
and XACCT Ltd's rules and regulations. You will be expected to sign and comply
with an Employment, Confidential Information, and Invention Assignment Agreement
that requires, among other provisions, the assignment of patent rights to any
invention made during your employment at the Company and non-disclosure of
proprietary information. Normal working hours are from 8:30a.m. to 6:00p.m,
Monday through Friday. Of course as an exempt employee you will be expected to
work additional hours as required by your assignments.

          To indicate your acceptance of the Company's offer, please sign and
date this letter in the space provided below and return it to me. A duplicate
original is enclosed for your records. This letter, along with the agreement
relating to proprietary rights between you and the Company, sets forth the terms
of your employment with the Company and supersedes any prior representations or
agreements, whether written or oral.

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          This letter may not be modified or amended except by a written
agreement, signed by an officer of the Company and by you.

          We look forward to having you on board.

                                    Sincerely,

                                    XACCT Technologies, Inc.

                                    /s/ Eric Gries

                                    Eric Gries
                                    President and CEO

ACCEPTED AND AGREED TO

This  ____ day of ________, 2000__.


/s/ Limor Schweitzer
--------------------------------
         Limor Schweitzer

Enclosures:   Duplicate Original Letter Employment, Confidential Information,
              and Invention Assignment Agreement