CERTIFICATION
I, Gifford R. Zimmerman, certify that:
1. I have reviewed this report on Form N-CSR of Nuveen Municipal Market
Opportunity Fund, Inc.;
2. Based on my knowledge, this report does not contain any untrue statement
of a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements were
made, not misleading with respect to the period covered by this report;
3. Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects the
financial condition, results of operations, changes in net assets, and cash
flows (if the financial statements are required to include a statement of cash
flows) of the registrant as of, and for, the periods presented in this report;
4. The registrant's other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Rule 30a-3(c) under the Investment Company Act of 1940) for the registrant and
have:
(a) designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the
registrant, including its consolidated subsidiaries, is made known to
us by others within those entities, particularly during the period in
which this report is being prepared;
(b) evaluated the effectiveness of the registrant's disclosure controls
and procedures and presented in this report our conclusions about the
effectiveness of the disclosure controls and procedures, as of a date
within 90 days prior to the filing date of this report based on such
evaluation; and
(c) disclosed in this report any change in the registrant's internal
control over financial reporting that occurred during the second
fiscal quarter of the period covered by this report that has
materially affected, or is reasonably likely to materially affect, the
registrant's internal control over financial reporting; and
5. The registrant's other certifying officer and I have disclosed to the
registrant's auditors and the audit committee of the registrant's board of
directors (or persons performing the equivalent functions):
(a) all significant deficiencies and material weaknesses in the design or
operation of internal control over financial reporting which are
reasonably likely to adversely affect the registrant's ability to
record, process, summarize, and report financial information; and
(b) any fraud, whether or not material, that involves management or other
employees who have a significant role in the registrant's internal
control over financial reporting.
Date: January 6, 2005 /s/ Gifford R. Zimmerman
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Chief Administrative Officer
(Principal Executive Officer)
CERTIFICATION
I, Stephen D. Foy, certify that:
1. I have reviewed this report on Form N-CSR of Nuveen Municipal Market
Opportunity Fund, Inc.;
2. Based on my knowledge, this report does not contain any untrue statement
of a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements were
made, not misleading with respect to the period covered by this report;
3. Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects the
financial condition, results of operations, changes in net assets, and cash
flows (if the financial statements are required to include a statement of cash
flows) of the registrant as of, and for, the periods presented in this report;
4. The registrant's other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Rule 30a-3(c) under the Investment Company Act of 1940) for the registrant and
have:
(a) designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the
registrant, including its consolidated subsidiaries, is made known to
us by others within those entities, particularly during the period in
which this report is being prepared;
(b) evaluated the effectiveness of the registrant's disclosure controls
and procedures and presented in this report our conclusions about the
effectiveness of the disclosure controls and procedures, as of a date
within 90 days prior to the filing date of this report based on such
evaluation; and
(c) disclosed in this report any change in the registrant's internal
control over financial reporting that occurred during the second
fiscal quarter of the period covered by this report that has
materially affected, or is reasonably likely to materially affect, the
registrant's internal control over financial reporting; and
5. The registrant's other certifying officer and I have disclosed to the
registrant's auditors and the audit committee of the registrant's board of
directors (or persons performing the equivalent functions):
(a) all significant deficiencies and material weaknesses in the design or
operation of internal control over financial reporting which are
reasonably likely to adversely affect the registrant's ability to
record, process, summarize, and report financial information; and
(b) any fraud, whether or not material, that involves management or other
employees who have a significant role in the registrant's internal
control over financial reporting.
Date: January 6, 2005 /s/ Stephen D. Foy
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Vice President and Controller
(Principal Financial Officer)