<Page>
Exhibit EX-99.CERT
CERTIFICATIONS
I, W. Douglas Beck, President of UBS Managed Municipal Trust, certify that:
1. I have reviewed this report on Form N-CSR of UBS Managed Municipal Trust;
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(s) 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) and
internal control over financial reporting (as defined in Rule 30a-3(d)
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) Designed such internal control over financial reporting, or
caused such internal control over financial reporting to be
designed under our supervision, to provide reasonable assurance
regarding the reliability of financial reporting and the
preparation of financial statements for external purposes in
accordance with generally accepted accounting principles;
(c) 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
(d) 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(s) 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):
<Page>
(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.
By: /s/ W. Douglas Beck
--------------------
W. Douglas Beck
President
Date: September 7, 2005
-----------------
I, Thomas Disbrow, Vice President and Treasurer of UBS Managed Municipal Trust,
certify that:
1. I have reviewed this report on Form N-CSR of UBS Managed Municipal Trust;
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(s) 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) and
internal control over financial reporting (as defined in Rule 30a-3(d)
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) Designed such internal control over financial reporting, or
caused such internal control over financial reporting to be
designed under our supervision, to provide reasonable assurance
regarding the reliability of financial reporting and the
preparation of financial statements for external purposes in
accordance with generally accepted accounting principles;
(c) Evaluated the effectiveness of the registrant's disclosure
controls and procedures and presented in this report our
conclusions about the effectiveness of the disclosure
<Page>
controls and procedures, as of a date within 90 days prior to
the filing date of this report based on such evaluation; and
(d) 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(s) 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.
By: /s/ Thomas Disbrow
------------------
Thomas Disbrow
Vice President and Treasurer
Date: September 7, 2005
-----------------