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                                                                    Exhibit 10.5

                        INVESTMENT SUB-ADVISORY AGREEMENT

         AGREEMENT made as of this 30th day of July 2003 by and between Nuveen
Institutional Advisory Corp., a Delaware corporation and a registered investment
adviser ("Manager"), and Wellington Management Company, LLP, a Massachusetts
limited liability partnership and a federally registered investment adviser
("Sub-Adviser").

         WHEREAS, Manager serves as the investment manager for the Nuveen
Diversified Dividend and Income Fund (the "Fund"), a closed-end management
investment company registered under the Investment Company Act of 1940, as
amended (the "1940 Act") pursuant to an Investment Management Agreement between
Manager and the Fund (as such agreement may be modified from time to time, the
"Management Agreement"); and

         WHEREAS, Manager desires to retain Sub-Adviser as its agent to furnish
investment advisory services for a certain designated portion of the Fund's
investment portfolio, upon the terms and conditions hereafter set forth;

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

         1.       Appointment. Manager hereby appoints Sub-Adviser to provide
certain sub-investment advisory services to the Fund for the period and on the
terms set forth in this Agreement. Sub-Adviser accepts such appointment and
agrees to furnish the services herein set forth for the compensation herein
provided.

         2.       Services to be Performed. Subject always to the supervision of
Fund's Board of Trustees and the Manager, Sub-Adviser will furnish an investment
program in respect of, make investment decisions for, and place all orders for
the purchase and sale of securities for the portion of the Fund's investment
portfolio allocated by Manager to Sub-Adviser, all on behalf of the Fund and as
described in the investment policy section of the Fund's initial registration
statement on Form N-2 as declared effective by the Securities and Exchange
Commission, as such policies described therein may subsequently be changed by
the Fund's Board of Trustees and publicly described. In the performance of its
duties, Sub-Adviser will satisfy its fiduciary duties to the Fund, will monitor
the Fund's investments in securities selected for the Fund by the Sub-Adviser
hereunder, and will comply with the provisions of the Fund's Declaration of
Trust and By-laws, as amended from time to time, and the stated investment
objectives, policies and restrictions of the Fund. Manager will provide
Sub-Adviser with current copies of the Fund's Declaration of Trust, By-laws,
prospectus and any amendments thereto, and any objectives, policies or
limitations not appearing therein as they may be relevant to Sub-Adviser's
performance under this Agreement. Sub-Adviser and Manager will each make its
officers and employees available to the other from time to time at reasonable
times to review investment policies of the Fund and to consult with each other
regarding the investment affairs of the Fund. Sub-Adviser will report to the
Board of Trustees and to Manager with respect to the implementation of such
program.

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         The Sub-Adviser will vote all proxies solicited by or with respect to
the issuers of securities which assets of the Fund's investment portfolio
allocated by Manager to Sub-Adviser are invested, consistent with its proxy
voting guidelines and based upon the best interests of the Fund. The Sub-Adviser
will maintain appropriate records detailing its voting of proxies on behalf of
the Fund and upon reasonable request will provide a report setting forth the
proposals voted on and how the Fund's shares were voted, including the name of
the corresponding issuers.

         Sub-Adviser is authorized to select the brokers or dealers that will
execute the purchases and sales of portfolio securities for the Fund, and is
directed to use its commercially reasonable efforts to obtain best execution,
which includes most favorable net results and execution of the Fund's orders,
taking into account all appropriate factors, including price, dealer spread or
commission, size and difficulty of the transaction and research or other
services provided. It is understood that the Sub-Adviser will not be deemed to
have acted unlawfully, or to have breached a fiduciary duty to the Fund, or be
in breach of any obligation owing to the Fund under this Agreement, or
otherwise, solely by reason of its having caused the Fund to pay a member of a
securities exchange, a broker or a dealer a commission for effecting a
securities transaction for the Fund in excess of the amount of commission
another member of an exchange, broker or dealer would have charged if the
Sub-Adviser determined in good faith that the commission paid was reasonable in
relation to the brokerage or research services provided by such member, broker
or dealer, viewed in terms of that particular transaction or the Sub-Adviser's
overall responsibilities with respect to its accounts, including the Fund, as to
which it exercises investment discretion. In addition, if in the judgment of the
Sub-Adviser, the Fund would be benefited by supplemental services, the
Sub-Adviser is authorized to pay spreads or commissions to brokers or dealers
furnishing such services in excess of spreads or commissions that another broker
or dealer may charge for the same transaction, provided that the Sub-Adviser
determined in good faith that the commission or spread paid was reasonable in
relation to the services provided. The Sub-Adviser will properly communicate to
the officers and trustees of the Fund such information relating to transactions
for the Fund as they may reasonably request. In no instance will portfolio
securities be purchased from or sold to the Manager, Sub-Adviser or any
affiliated person of either the Fund, Manager, or Sub-Adviser, except as may be
permitted under the 1940 Act;

         Sub-Adviser further agrees that it:

         (a)      will use the same degree of skill and care in providing such
                  services as it uses in providing services to fiduciary
                  accounts for which it has investment responsibilities;

         (b)      will conform to all applicable Rules and Regulations of the
                  Securities and Exchange Commission in all material respects
                  and in addition will conduct its activities under this
                  Agreement in accordance with any applicable regulations of any
                  governmental authority pertaining to its investment advisory
                  activities;

         (c)      will report regularly to Manager and to the Board of Trustees
                  of the Fund and will make appropriate persons available for
                  the purpose of reviewing with representatives of Manager and
                  the Board of Trustees on a regular basis at

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                  reasonable times the management of the Fund, including,
                  without limitation, review of the general investment
                  strategies of the Fund with respect to the portion of the
                  Fund's portfolio allocated to the Sub-Adviser, the performance
                  of the Fund's investment portfolio allocated to the
                  Sub-Adviser in relation to standard industry indices and
                  general conditions affecting the marketplace and will provide
                  various other reports from time to time as reasonably
                  requested by Manager;

         (d)      will monitor the pricing of portfolio securities, and events
                  relating to the issuers of those securities and the markets in
                  which the securities trade in the ordinary course of managing
                  the portfolio securities of the Fund, and will notify Manager
                  promptly of any issuer-specific or market events or other
                  situations that occur (particularly those that may occur after
                  the close of a foreign market in which the securities may
                  primarily trade but before the time at which the Fund's
                  securities are priced on a given day) that may materially
                  impact the pricing of one or more securities in Sub-Adviser's
                  portion of the portfolio. In addition, Sub-Adviser will assist
                  Manager in evaluating the impact that such an event may have
                  on the net asset value of the Fund and in determining a
                  recommended fair value of the affected security or securities;
                  and

         (e)      will prepare such books and records with respect to the Fund's
                  securities transactions for the portion of the Fund's
                  investment portfolio allocated to the Sub-Adviser as requested
                  by the Manager and will furnish Manager and Fund's Board of
                  Trustees such periodic and special reports as the Board or
                  Manager may reasonably request.

         (f)      The Sub-Adviser is prohibited from consulting with any other
                  sub-adviser of the Fund or any other sub-adviser to a fund
                  under common control with the Fund concerning transactions of
                  the Fund in securities or other assets.

         3.       Expenses. During the term of this Agreement, Sub-Adviser will
pay all expenses incurred by it in connection with its activities under this
Agreement other than the cost of securities (including brokerage commissions, if
any) purchased for the Fund.

         4.       Compensation. For the services provided and the expenses
assumed pursuant to this Agreement, Manager will pay the Sub-Adviser, and the
Sub-Adviser agrees to accept as full compensation therefor, a portfolio
management fee equal to the portion specified below of the investment management
fee payable by the Fund to the Manager, pursuant to the Management Agreement,
with respect to the Sub-Adviser's allocation of Fund net assets (including net
assets attributable to FundPreferred Shares and the principal amount of any
borrowings), as the net amount of such fee is reduced by the obligation of
Manager to reimburse certain fees and expenses to the Fund pursuant to an
Expense Reimbursement Agreement of even date herewith by and between the Fund
and the Manager, as such agreement may be modified from time to time:

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<TABLE>
<CAPTION>
                                    PERCENTAGE OF NET
       DAILY NET ASSETS               MANAGEMENT FEE
<S>                                 <C>
Up to $125 million                        50.0%
$125 million to $150 million              47.5%
$150 million to $175 million              45.0%
$175 million to $200 million              42.5%
$200 million and over                     40.0%
</TABLE>

The portfolio management fee shall accrue on each calendar day, and shall be
payable monthly on the first business day of the next succeeding calendar month.
The daily fee accrual shall be computed by multiplying the fraction of one
divided by the number of days in the calendar year by the applicable annual rate
of fee, and multiplying this product by the net assets of the Fund allocated to
the Sub-Advisor, determined in the manner established by the Fund's Board of
Trustees, as of the close of business on the last preceding business day on
which the Fund's net asset value was determined.

For the month and year in which this Agreement becomes effective or terminates,
there shall be an appropriate proration on the basis of the number of days that
the Agreement is in effect during the month and year, respectively.

Manager shall not agree to amend the financial terms of the Expense
Reimbursement Agreement or the Management Agreement to the detriment of the
Sub-Adviser by operation of this Section 4 without the express written consent
of the Sub-Adviser.

         5.       Services to Others. Manager understands, and has advised
Fund's Board of Trustees, that Sub-Adviser now acts, or may in the future act,
as an investment adviser to fiduciary and other managed accounts, and as
investment adviser or sub-investment adviser to one or more other investment
companies that are not a series of the Fund, provided that whenever the Fund and
one or more other investment advisory clients of Sub-Adviser have available
funds for investment, investments suitable and appropriate for each will be
allocated in a manner believed by Sub-Adviser to be equitable to each. Manager
recognizes, and has advised Fund's Board of Trustees, that in some cases this
procedure may adversely affect the size of the position that the Fund may obtain
in a particular security. It is further agreed that, on occasions when the
Sub-Adviser deems the purchase or sale of a security to be in the best interests
of the Fund as well as other accounts, it may, to the extent permitted by
applicable law, but will not be obligated to, aggregate the securities to be so
sold or purchased for the Fund with those to be sold or purchased for other
accounts in order to obtain favorable execution and lower brokerage commissions.
In addition, Manager understands, and has advised Fund's Board of Trustees, that
the persons employed by Sub-Adviser to assist in Sub-Adviser's duties under this
Agreement will not devote their full such efforts and service to the Fund. It is
also agreed that the Sub-Adviser may use any supplemental research obtained for
the benefit of the Fund in providing investment advice to its other investment
advisory accounts or for managing its own accounts.

         6.       Limitation of Liability. The Sub-Adviser shall not be liable
for, and Manager will not take any action against the Sub-Adviser to hold
Sub-Adviser liable for, any error of judgment or mistake of law or for any loss
suffered by the Fund (including, without limitation, by reason of the purchase,
sale or retention of any security) in connection with the performance of the
Sub-

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Adviser's duties under this Agreement, except for a loss resulting from willful
misfeasance, bad faith or gross negligence on the part of the Sub-Adviser in the
performance of its duties under this Agreement, or by reason of its reckless
disregard of its obligations and duties under this Agreement.

         7.       Term; Termination; Amendment. This Agreement shall become
effective with respect to the Fund on the same date as the Management Agreement
between the Fund and the Manager becomes effective, provided that it has been
approved by a vote of a majority of the outstanding voting securities of the
Fund in accordance with the requirements of the 1940 Act, and shall remain in
full force until August 1, 2005 unless sooner terminated as hereinafter
provided. This Agreement shall continue in force from year to year thereafter
with respect to the Fund, but only as long as such continuance is specifically
approved for the Fund at least annually in the manner required by the 1940 Act
and the rules and regulations thereunder; provided, however, that if the
continuation of this Agreement is not approved for the Fund, the Sub-Adviser may
continue to serve in such capacity for the Fund in the manner and to the extent
permitted by the 1940 Act and the rules and regulations thereunder.

         This Agreement shall automatically terminate in the event of its
assignment and may be terminated at any time without the payment of any penalty
by the Manager on no less than sixty (60) days' written notice to the
Sub-Adviser. This Agreement may be terminated by the Sub-Adviser without cause
after July 31, 2005 without payment of any penalty on no less than sixty (60)
days' prior written notice to the Manager. This Agreement may also be terminated
by the Fund with respect to the Fund by action of the Board of Trustees or by a
vote of a majority of the outstanding voting securities of such Fund on no less
than sixty (60) days' written notice to the Sub-Adviser by the Fund.

         This Agreement may be terminated with respect to the Fund at any time
without the payment of any penalty by the Manager, the Board of Trustees or by
vote of a majority of the outstanding voting securities of the Fund in the event
that it shall have been established by a court of competent jurisdiction that
the Sub-Adviser or any officer or director of the Sub-Adviser has taken any
action that results in a breach of the covenants of the Sub-Adviser set forth
herein.

         The terms "assignment" and "vote of a majority of the outstanding
voting securities" shall have the meanings set forth in the 1940 Act and the
rules and regulations thereunder.

         Termination of this Agreement shall not affect the right of the
Sub-Adviser to receive payments on any unpaid balance of the compensation
described in Section 4 earned prior to such termination. This Agreement shall
automatically terminate in the event the Management Agreement between the
Manager and the Fund is terminated, assigned or not renewed.

         8.       Notice. Any notice under this Agreement shall be in writing,
addressed and delivered or mailed, postage prepaid, to the other party

         If to the Manager:                   If to the Sub-Adviser:

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         Nuveen Institutional Advisory Corp.  Wellington Management Company, LLP
         333 West Wacker Drive                75 State Street
         Chicago, Illinois 60606              Boston, Massachusetts 02109
         Attention: John P. Amboian           Attention: Katy D. Burke

         With a copy to:                      With a copy to:

         Nuveen Investments, Inc.             s/a
         333 West Wacker Drive                ---------------------
         Chicago, Illinois 60606              same as above
         Attention: General Counsel           Attention: General Counsel

or such address as such party may designate for the receipt of such notice.

         9.       Limitations on Liability. All parties hereto are expressly put
on notice of the Fund's Agreement and Declaration of Trust and all amendments
thereto, a copy of which is on file with the Secretary of the Commonwealth of
Massachusetts, and the limitation of shareholder and trustee liability contained
therein. The obligations of the Fund entered in the name or on behalf thereof by
any of the Trustees, representatives or agents are made not individually but
only in such capacities and are not binding upon any of the Trustees, officers,
or shareholders of the Fund individually but are binding upon only the assets
and property of the Fund, and persons dealing with the Fund must look solely to
the assets of the Fund and those assets belonging to the subject Fund, for the
enforcement of any claims.

         10.      References to the Sub-Adviser. The Manager may not use the
names "Wellington" "Wellington Management" or "Wellington Management Company,
LLP" or any variations thereof or the logo of the Sub-Adviser or any affiliate
in the Fund's registration statement or any promotional or sales materials
without the prior approval of the Sub-Adviser, which the Sub-Adviser may grant
in its sole discretion. The Sub-Adviser shall provide to the Manager upon
reasonable request information relating to it for inclusion in any promotional
materials, and shall review and approve prior to first use any statements in
such promotional materials relating to the Sub-Adviser and its affiliates. The
Sub-Adviser will prepare and/or review such promotional materials on a basis
which it believes in good faith is accurate, not misleading and appropriate
under the circumstances. In connection with any such assistance, the Manager
understands and agrees that it is the sole responsibility of the Manager to
ensure that the contents, distribution and use of any promotional materials that
are required to be filed with the National Association of Securities Dealers
comply at all times with any applicable provisions of law in any relevant
jurisdiction. The Manager further understands and agrees that the Sub-Adviser
has no expertise in such laws and has not prepared or reviewed the promotional
materials with reference to such laws, and that the Manager's approval of the
contents of the promotional materials shall constitute its agreement that the
contents thereof comply with such law.

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         11.      Miscellaneous. The captions in this Agreement are included for
convenience of reference only and in no way define or delimit any of the
provisions hereof or otherwise affect their construction or effect. If any
provision of this Agreement is held or made invalid by a court decision,
statute, rule or otherwise, the remainder of this Agreement will not be affected
thereby. This Agreement will be binding upon and shall inure to the benefit of
the parties hereto and their respective successors.

         12.      Applicable Law. This Agreement shall be construed in
accordance with applicable federal law and (except as to Section 9 hereof which
shall be construed in accordance with the laws of Massachusetts) the laws of the
State of Illinois.

         IN WITNESS WHEREOF, the Manager and the Sub-Adviser have caused this
Agreement to be executed as of the day and year first above written.

NUVEEN INSTITUTIONAL ADVISORY          WELLINGTON MANAGEMENT
CORP., a Delaware corporation          COMPANY, LLP., a Massachusetts limited
                                       liability partnership

By:  /s/ Edward F. Neild, IV           By: /s/ Jonathan M. Payson
     -----------------------               ------------------------
Title: Managing Director               Title: Senior Vice President

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