Document:

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                                                                    Exhibit 10.6

                                VOTING AGREEMENT

         This Voting Agreement (this "Agreement") is made and entered into as of
this 24th day of March, 2000 by and between ERESEARCHTECHNOLOGY, INC., a
Delaware corporation ("eRT"), and PREMIER RESEARCH WORLDWIDE, LTD., a Delaware
corporation ("PRWW").

                                 R E C I T A L S

         eRT is preparing to file with the Securities Exchange Commission a Form
S-1 Registration Statement (the "Offering"). Following completion of the
Offering, PRWW will own at least a majority of the outstanding Common Stock, par
value $0.01 per share, of eRT, regardless of whether or not the Underwriters'
over-allotment option is exercised in whole or in part. In connection with the
Offering, PRWW and eRT have agreed to enter into this Agreement with respect to
and so as to ensure the election of at least three (3) independent directors of
eRT.

                                A G R E E M E N T

         NOW, THEREFORE, in consideration of the premises and the mutual
covenants herein contained, the parties hereto agree as follows:

         1. After the completion of the Offering, PRWW agrees that it will vote
all of its shares of Common Stock at any meeting at which (or in any stockholder
action taken by written consent in lieu of a meeting in which) directors are
elected in favor of those nominees for election as eRT directors who are
nominated by the eRT Board of Directors and who are not affiliates of PRWW,
employees of PRWW or directors of PRWW ("Independent Directors") so that if such
nominees were elected there would be at least three (3) Independent Directors
who are members of the Board of Directors of eRT.

         2. This Agreement will automatically terminate on that date upon which
PRWW beneficially owns shares of capital stock of eRT entitled to cast 30% or
less of all votes entitled to be cast for the election of directors at a meeting
at which stockholders holding all outstanding voting shares of eRT were present
and voting.

         3. Miscellaneous:

                  a. Each party covenants that at any time, and from time to
time, it will execute such additional instruments and take such additional
actions as may be reasonably necessary or reasonably requested by the other
party to confirm or otherwise carry out the intent and purposes of this
Agreement.

                  b. The parties mutually agree that if a violation of Section 1
of this Agreement occurs, such violation or threatened violation will cause
irreparable injury to eRT and the remedy at law for any such violation or
threatened violation will be

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inadequate. PRWW therefore agrees that eRT shall be entitled to appropriate
equitable relief, including but not limited to specific performance, in addition
to any other remedy that might be available at law or in equity.

                  c. This Agreement may be modified or amended from time to time
only by a written instrument executed by the parties hereto.

                  d. This Agreement shall be binding upon, and inure to the
benefit of, the parties hereto and their respective successors and assigns.

                  e. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Pennsylvania, without regard to its
conflicts of law rule.

                  f. This Agreement embodies the entire understanding between
the parties hereto with respect to subject matters covered hereby and supersedes
any prior agreement or understanding between the parties with respect to such
matters.

                  g. This Agreement may be executed in multiple counterpart
copies, each of which shall be considered an original and all of which shall
constitute one and the same instrument.

                  h. This Agreement is not assignable.

         IN WITNESS WHEREOF, the undersigned have executed this Agreement as of
the day and year first above written.

                                             ERESEARCHTECHNOLOGY, INC.,
                                             a Delaware corporation

                                             By: /s/ Joseph Esposito
                                                 -----------------------------
                                                 Name:
                                                       -----------------------
                                                 Title:
                                                       -----------------------

                                             PREMIER RESEARCH WORLDWIDE,
                                             LTD., a Delaware corporation

                                             By: /s/ Joel Morganroth
                                                 -----------------------------
                                                 Name:
                                                       -----------------------
                                                 Title:
                                                       -----------------------<PAGE>

                              TAX SHARING AGREEMENT
                              ---------------------

         TAX SHARING AGREEMENT (the "Agreement") dated as of January 1, 2000
between Premier Research Worldwide, Ltd. ("PRWW") and eResearch Technology, Inc.
("ERT").

         Whereas, PRWW and ERT have joined in the filing of a consolidated
federal income tax return for a group of affiliated companies of which PRWW is
the common parent and ERT is a member (the "PRWW Consolidated Group"); and

         Whereas, PRWW and ERT wish to provide for the payment of tax
liabilities and entitlement to refunds, allocate responsibility and provide for
cooperation in the filing of tax returns, provide for the realization and
payment of tax benefits arising out of adjustments to the tax returns of the
parties, and to provide for certain other matters;

         NOW, THEREFORE, in consideration of the mutual covenants contained
herein and intending to be legally bound, PRWW and ERT agree as follows:

         1.       Definitions.

         For purposes of this Agreement:

                  (a) "Taxes" means all federal, state, local, foreign and other
net income, gross income, gross receipts, sales, use, ad valorem, transfer,
franchise, profits, license, lease, service, service use, withholding, payroll,
employment, excise, severance, stamp, occupation, premium, property (including,
without limitation, real property taxes and any assessments, special or
otherwise), windfall profits, customs, duties or other taxes, fees, assessments
or charges of any kind whatever, together with any interest and any penalties,
additions to tax or additional amounts with respect thereto (and "Tax" means any
one of the foregoing Taxes).

                  (b) "Returns" means all returns, declarations, reports,
statements and other documents required under a Tax Law (as hereinafter defined)
either (i) to be filed with a Governmental Authority (as hereinafter defined) in
respect of Taxes; or (ii) to be provided to a person other than a Governmental
Authority (and "Return" means any one of the foregoing Returns).

                  (c) "Code" means the Internal Revenue Code of 1986, as
amended. All citations to the Code, or to the Treasury Regulations promulgated
thereunder, shall include any amendments or any substitute or successor
provisions thereto.

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                  (d) "Section" means a section of this Agreement, unless
indicated otherwise.

                  (e) "Governmental Authority" means the government of the
United States or any foreign country or any state, province, municipality or
other political subdivision of the United States or any foreign identity, or any
agency, department, board, instrumentality, authority or commission (including
regulatory and administrative bodies) of any of the foregoing.

                  (f) "Tax Law" means a statute, regulation or administrative
rule enacted or promulgated for the determination, imposition, assessment or
collection of any Tax.

                  (g) "Separate Tax Liability" means the amount, if any, in
excess of (i) the "Tax Liability" (as herein defined) of the PRWW Consolidated
Group for a taxable year determined by including ERT and its subsidiaries as
members of that group as required under applicable Tax Law over (ii) the amount
of Tax Liability of the PRWW Consolidated Group for such year determined as if
ERT and its subsidiaries were not members of the group. If the amount calculated
in subsection (ii) of this Section (1)(g) exceeds the amount calculated in
subsection (i) of this Section (1)(g), such excess shall be a "Separate Tax
Benefit."

                  (h) "Tax Liability" means taxable income reduced by any loss
carryforwards and dividends received deduction multiplied by the applicable Tax
rate under federal Tax Law, less any credits, plus the Alternative Minimum Tax
(as defined in Section 55 of the Code), plus or minus any additional adjustments
required to compute the final Tax Liability under federal Tax Law.

                  (i) "Accounting Firm" means (i) the nationally recognized
accounting firm that is the principal independent auditor of both PRWW and ERT
at the time of a dispute governed by Section 7 hereof; or (ii) if the firm
described in clause (i) is unwilling or unable to serve under Section 7, the
nationally recognized accounting firm appointed by the firm described in clause
(i); or (iii) if PRWW and ERT do not use the same accounting firm as their
principal independent auditor, then the nationally recognized accounting firm
jointly selected by the principal independent auditors of PRWW and ERT at the
time of a dispute governed by Section 7 hereof.

                  (j) "Disaffiliation" means any event that results in ERT no
longer being a member of the PRWW Consolidated Group.

                  (k) "Disaffiliation Date" means the date on which
Disaffiliation occurs.

                                      - 2 -

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         2.       Returns and Payments.

                  (a)(i) Filing of Returns. PRWW shall timely prepare and file,
or cause to be timely prepared and filed, all consolidated Returns of PRWW that
include ERT and its subsidiaries. ERT and PRWW agree that they will treat the
Disaffiliation Date as the last day of a taxable period with respect to ERT and
its subsidiaries for any consolidated Taxes and will file all Tax Returns with
respect to such Taxes accordingly, unless such treatment is not permitted under
the applicable Tax Law. The preparation and filing of all Tax Returns with
respect to ERT and its subsidiaries for periods beginning after the
Disaffiliation Date are the sole responsibility of ERT. ERT agrees to cooperate
with PRWW in the preparation of any consolidated Returns of PRWW that include
ERT and its subsidiaries, or any portion thereof, and, at ERT's expense, to
provide PRWW at least 60 days before the applicable Return is required to be
filed (including extensions) with tax return packages and such other information
as PRWW shall reasonably request for the preparation of such Returns.

                   (ii) Payments. PRWW shall timely remit or cause to be
remitted, all Taxes payable with respect to Returns which PRWW is obligated to
prepare and file pursuant to Section 2(a)(i) and, except as otherwise provided
herein, shall be liable for all such Taxes and shall be entitled to any refund
of, or credit for, such Taxes. ERT agrees to pay to PRWW, with respect to any
Return filed by PRWW pursuant to Section 2(a)(i), an amount equal to the
Separate Tax Liability, if any, determined for the taxable year for which such
Return is filed. PRWW agrees to pay to ERT, with respect to any Return filed by
PRWW pursuant to Section 2(a)(i), an amount equal to the Separate Tax Benefit,
if any, determined for the taxable year for which such Return is filed. For all
tax periods beginning prior to the Disaffiliation Date, ERT will remit quarterly
estimated Tax payments to PRWW as though ERT and its subsidiaries were filing
their own separate federal income tax returns. The calculation of such estimates
shall be provided by ERT and submitted to PRWW for its approval (which shall not
be unreasonably withheld) at least 15 days prior to the date estimated Tax
payments would have otherwise been due. ERT will remit such quarterly estimated
payments to PRWW no later than five days before the PRWW Consolidated Group's
estimated Tax payments are due. No later than five days after ERT has received
from PRWW a final calculation of ERT's Separate Tax Liability under this Section
2(a)(ii) based on completed Tax Returns for the relevant taxable year, ERT will
pay to PRWW the excess, if any, of ERT's Separate Tax Liability over the sum of
all prior payments, if any, made by ERT to PRWW with respect to such year. If
such final calculation under this Section 2(a)(ii) demonstrates that ERT's
estimated payments exceed the Separate Tax Liability or that ERT has a Separate
Tax Benefit, the excess plus any Separate Tax Benefit will be credited to ERT's
Tax liability for the subsequent tax year, or if the subsequent tax year is a
year beginning after the Disaffiliation Date, PRWW will pay such excess or
Separate Tax Benefit to ERT no later than 30 days after filing all Tax Returns
related to periods beginning before the Disaffiliation Date. All payments
required under this Section 2(a)(ii) will be paid by ERT to PRWW or by PRWW to
ERT, as the case may be, regardless of whether ERT is a member of the PRWW
Consolidated Group.

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                   (iii) Subsequent Adjustments. If the items used to determine
the Separate Tax Liability or Separate Tax Benefit under Section 2(a)(ii) are
adjusted by reason of an amended return, claim for refund, examination by a
Governmental Authority, or the final decision of any court, the amount due from
or to ERT under Section 2(a)(ii) shall be recomputed using the adjusted Separate
Tax Liability or adjusted Separate Tax Benefit. ERT agrees to pay to PRWW any
additional amount owed including statutory interest at the rate applicable to
underpayments of the PRWW Consolidated Group (with full credit given for any
prior payments for the year), and PRWW agrees to pay to ERT any overpayment made
by ERT including statutory interest at the rate applicable to overpayments of
the PRWW Consolidated Group.

                  Payments to be made by PRWW to ERT pursuant to this Section
2(a)(iii) shall be made, in the case of a refund, within 30 days after PRWW has
received such refund. In the case of a credit, such payments by PRWW to ERT
shall be made within 30 days after PRWW has received written notification from a
Governmental Authority reflecting adjustments for such credit to a Return of the
PRWW Consolidated Group. Payments to be made by ERT to PRWW shall be made, in
the case of any additional Tax, no later than five days before the due date of
any required Tax payment by PRWW. In the case of a reduction in credit of Tax,
such payment by ERT to PRWW shall be made within 30 days after PRWW has received
written notification from a Governmental Authority reflecting an adjustment for
such reduction to a Return of the PRWW Consolidated Group.

                  Notwithstanding anything in this Section 2(a)(iii), the
treatment of carrybacks of net operating losses, net capital losses and tax
credits shall be governed by Section 2(a)(iv). All additional payments required
under this Section 2(a)(iii) will be paid by ERT to PRWW or by PRWW to ERT, as
the case may be, regardless of whether ERT is a member of the PRWW Consolidated
Group.

                     (iv) Carrybacks. Where permitted by applicable Tax Law,
PRWW shall be allowed, if it so chooses, to carry back any consolidated net
operating loss, consolidated net capital loss or consolidated tax credit, as
defined in Treasury Regulation Sections 1.1502-21(e), 1.1502-22(b) and
1.1502-79(c) and (d) respectively, ("Consolidated Carryback Item") that arises
in any taxable year beginning before the Disaffiliation Date, to a taxable year
of any consolidated Return filed by PRWW. If a Consolidated Carryback Item is
carried back to a taxable year of any consolidated Return filed by PRWW, and is
absorbed or used in whole or in part in such year, PRWW shall pay ERT an amount
equal to the excess, if any, of the amount of such refund, credit or tax
reduction (net of any income taxes payable thereon) determined by including ERT
as a member of the PRWW Consolidated Group, over the amount of such items
determined by excluding ERT from the PRWW Consolidated Group, provided however,
that such excess shall be reduced by any amount due PRWW from ERT under Section
2(a)(ii) and (iii). Amounts due pursuant to this paragraph shall be paid in full
within 30 days after PRWW receives a refund or credit, or otherwise realizes the
benefit of the adjustment if no refund or credit is payable.

                                      - 4 -

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         If a refund, credit or tax reduction attributable to a Consolidated
Carryback Item is later reduced (for example, as a result of a reduction in the
amount of a Consolidated Carryback Item caused by an audit adjustment), ERT
shall pay to PRWW an amount equal to the extent that such reduction is
attributable to ERT (determined in the same manner as in the immediately
preceeding paragraph) including statutory interest at a rate applicable to
underpayments of the PRWW Consolidated Group. Any such payment shall be made to
PRWW no later than five days before the due date of any required Tax payment by
PRWW or, if no payment is due, within 30 days after the final determination of
the amount of the reduction in such benefit.

         Where permitted by applicable Tax Law, ERT and its subsidiaries shall
be allowed, if they so choose, to carry back any net operating loss, net capital
loss or tax credit ("ERT Carryback Item") that arises in any taxable year
beginning after the Disaffiliation Date, to a taxable year of any consolidated
Return filed by PRWW. If an ERT Carryback Item is carried back to a taxable year
of any consolidated Return filed by PRWW, and is absorbed or used in whole or in
part in such year, PRWW shall pay ERT an amount equal to any refund, credit or
tax reduction attributable to such ERT Carryback Item, provided that such refund
is received by PRWW or PRWW realizes the benefit of any credit or tax reduction.
The amount of any such refund, credit or tax reduction attributable to the ERT
Carryback Item shall be equal to the difference between the amount of such
refund, credit or tax reduction (net of any income taxes payable thereon) with
and without the ERT Carryback Item and shall be reduced by any amount due PRWW
from ERT under Section 2(a)(ii) and (iii). Amounts due pursuant to this
paragraph shall be paid in full within 30 days after PRWW receives a refund or
credit, or otherwise realizes the benefit of the adjustment if no refund or
credit is payable.

                  If a refund, credit or tax reduction attributable to an ERT
Carryback Item is later reduced (for example, as a result of a reduction in the
amount of an ERT Carryback Item caused by an audit adjustment), ERT shall pay to
PRWW the amount of such reduction including statutory interest at a rate
applicable to underpayments of the PRWW Consolidated Group. Any such payment
shall be made to PRWW no later than five days before the due date of any
required Tax payment by PRWW or, if no payment is due, within 30 days after the
final determination of the amount of the reduction in such benefit.

                  PRWW shall be responsible for preparing and filing (or
arranging for the preparation and filing of) any Returns required to carry back
an ERT Carryback Item to a taxable year of PRWW. ERT shall reimburse PRWW for
the reasonable out-of-pocket cost of preparation of any such Returns. ERT shall
indemnify PRWW for any penalty or interest incurred by PRWW that is attributable
to ERT Carryback Items.

                  ERT may choose at its own discretion to carry back an ERT
Carryback Item to taxable years in respect of any Return not originally filed by
PRWW pursuant to Section 2(a)(i). ERT shall be entitled to any refund, or the
benefit of any credit or tax reduction, resulting from such carryback and shall
be responsible for preparing and timely filing any Returns with respect to such
carryback.

                                      - 5 -

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                  (v) State Taxes. To the extent appropriate, rules similar to
the other provisions of Section 2 shall be applied to the filing of state
franchise or income tax Returns and the payment of state franchise or income tax
liabilities to which ERT and PRWW are subject and which are required to be
determined on a unitary, combined or consolidated basis.

                 (b)(i) Filing of Other Returns. ERT shall timely prepare and
file, or cause to be timely prepared and filed, all Returns of ERT and its
subsidiaries required to be filed before, on or after the Disaffiliation Date,
other than those Returns required to be filed by PRWW pursuant to Section
2(a)(i).

                   (ii) Payments. ERT shall be liable for, and shall timely pay,
or cause to be paid, all Taxes with respect to Returns which ERT is obligated to
prepare and file pursuant to Section 2(b)(i) and shall be liable for all Taxes
with respect to any other Returns filed by, or in respect of, ERT and its
subsidiaries, other than any Returns filed by PRWW pursuant to Section 2(a)(i),
and shall be entitled to any refund of, or credit for, such Taxes. PRWW shall
not be liable for any Taxes payable with respect to such Returns of ERT and its
subsidiaries.

         3.       Disaffiliation of ERT.

         Except for Section 2(a)(iv) regarding Carrybacks, this Agreement shall
have no application and PRWW, the PRWW Consolidated Group or ERT shall have no
obligation to each under this Agreement with respect to any taxable period that
begins after the Disaffiliation Date; provided, that this Agreement shall apply
to any final short taxable period of ERT. After the filing of all Tax Returns
related to periods beginning before the Disaffiliation Date, ERT will be
informed of the amount of consolidated carryovers as of the end of such taxable
year or period that are attributable to ERT, as provided by applicable Tax Law.

         4.       Record Retention.

         After the Disaffiliation Date, PRWW and ERT shall each make available
to the other, as reasonably requested, and to any Governmental Authority that is
duly authorized to request information, records or documents, all information,
records or documents of PRWW and ERT and its subsidiaries for all periods prior
to or including the Disaffiliation Date and shall preserve all such information,
records and documents until the expiration of any applicable statute of
limitations including extensions thereof, provided that notice of any such
extension is given to the party which did not grant the extension.

                                      - 6 -

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         5.       Audits and Contests.

         PRWW shall, at its expense, have the right to control on the taxpayer's
behalf any Tax audit and any administrative or court proceeding concerning Taxes
for which PRWW is responsible for filing a Return under Section 2(a)(i) and to
concede, compromise or contest any assessment or assertion of liability with
respect to any such Taxes, provided, however, that ERT will be entitled to
participate in any such audit or proceeding concerning Taxes for which ERT is
liable under Section 2 and PRWW shall not concede, compromise or contest any
assessment or assertion of liability with respect to any such Taxes for which
ERT is liable under Section 2 without the consent of ERT (which consent shall
not be unreasonably withheld).

         ERT shall, at its expense, have the right to control on the taxpayer's
behalf any Tax audit and any administrative or court proceeding concerning Taxes
for which ERT is responsible for filing a Return under Section 2(b)(i) and to
concede, compromise or contest any assessment or assertion of liability with
respect to any such Taxes.

         6.       Duty to Cooperate.

         PRWW and ERT shall provide reasonable cooperation to each other in
connection with (i) the preparation or filing of any Return, Tax election, Tax
consent or certification, or any claim for refund, (ii) any determination of
liability for Taxes, and (iii) any audit, examination or other proceeding in
respect of Taxes of PRWW. Such cooperation shall include making available, on a
reasonable basis, employees of PRWW or ERT, as the case may be, whose out-
of-pocket costs, if any, such as travel and lodging, shall be reimbursed by the
party to which such employees are made available.

         7.    Dispute Resolution.

         In the event of a dispute concerning this Agreement, the parties shall,
in good faith, attempt to resolve such dispute. If the dispute is not resolved
then the parties shall submit such dispute to the Accounting Firm whose decision
shall be binding on the parties. The Accounting Firm's fee shall be borne
equally by PRWW and ERT.

         8.   Notices.

         All notices and other communications required or permitted hereunder
shall be in writing and shall be given by hand delivery, telecopier, commercial
courier service with guaranteed one-day delivery, or prepaid first class mail
to the following addresses:

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<PAGE>

                       If to PRWW:
                             Premier Research Worldwide, Ltd.
                             Attention: Chairman
                             30 South 17th Street
                             Philadelphia, PA 19103

                       If to ERT:
                             eResearchTechnology, Inc.
                             Attention: President and Chief Executive Officer
                             30 South 17th Street
                             Philadelphia, PA 19103

          9.      Successors.

         This Agreement shall be binding on and inure to the benefit of any
successor, by merger, acquisition of assets or otherwise, to any of the parties
hereto (including but not limited to any successor of PRWW or ERT succeeding to
the tax attributes of either under Section 381 of the Code), to the same extent
as if the successor had been an original party to this Agreement.

         10.      Amendments.

         This Agreement shall not be modified, amended, supplemented or
terminated except in writing executed by both parties hereto.

         11.      Governing Law.

         This Agreement shall be governed by and interpreted in accordance with
the laws of the State of Pennsylvania.

                                     Premier Research Worldwide, Ltd.

                                     By:   /s/ Joel Morganroth
                                        ------------------------
                                           Joel Morganroth, M.D.
                                           Chairman and Chief Executive Officer

                                     eResearch Technology, Inc.

                                     By:   /s/ Joseph A. Esposito
                                        ---------------------------
                                           Joseph A. Esposito,
                                           President and Chief Executive Officer

                                      - 8 -

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