Fitch Affirms Preferred Share Ratings of 2 Pioneer Municipal Closed End Funds at 'AAA'

NEW YORK--(BUSINESS WIRE)--

Fitch Ratings has affirmed the 'AAA' ratings assigned to the following auction market preferred shares (AMPS) issued by Pioneer Municipal High Income Trust MHI and Pioneer Municipal High Income Advantage Trust MAV, both of which are leveraged municipal closed-end funds advised by Pioneer Investments Management (Pioneer):

Pioneer Municipal High Income Trust (MHI):

--$50,000,000 of auction market preferred shares, series A, with a liquidation preference of $25,000 per share;

--$51,000,000 of auction market preferred shares, series B, with a liquidation preference of $25,000 per share.

Pioneer Municipal High Income Advantage Trust (MAV):

--$75,000,000 of auction market preferred shares, series A, with a liquidation preference of $25,000 per share;

--$75,000,000 of auction market preferred shares, series B, with a liquidation preference of $25,000 per share.

KEY RATING DRIVERS

The 'AAA' rating affirmations reflects:

--Sufficient asset coverage provided to the AMPS by the underlying portfolios of assets;

--The structural protections afforded by mandatory de-leveraging provisions in the event of asset coverage declines;

--The legal and regulatory parameters that govern the funds' operations;

--The capabilities of Pioneer as investment advisor.

CAPITAL STRUCTURE

As of Jan. 27, 2012, MHI's total assets were approximately $406 million. The fund had $101 million in AMPS and had floating rate securities of tender option bonds in an amount of $81 million. As of the same date, MAV's total assets were approximately $438 million. The fund had $150 million in AMPS and had floating rate securities of tender option bonds in an amount of $57 million.

ASSET COVERAGE

At the time of the rating affirmations, the funds' asset coverage ratios, as calculated in accordance with the Fitch total and net overcollateralization tests (Fitch OC tests) per the 'AAA' rating guidelines outlined in Fitch's applicable criteria, were in excess of 100%, which is the minimum asset coverage amount deemed consistent with an 'AAA' rating. The funds' governing documents require that asset coverage for the AMPS, as calculated in accordance with the Fitch OC tests, be maintained in excess of 100%. Should the asset coverage decline below 100%, the governing documents require the funds to restore compliance within a 40 business-day period.

Additionally, as of the same date, the funds' asset coverage ratios for total outstanding AMPS, as calculated in accordance with Pioneer's interpretation of the Investment Company Act of 1940, were in excess of 200%, which is also a minimum asset coverage required by the funds' governing documents.

PIONEER MUNICIPAL HIGH INCOME TRUST (MHI)

MHI is a diversified closed-end management investment company, registered under the Investment Company Act of 1940, as amended, that commenced investment operations in July 2003. The fund seeks to provide a high level of current income exempt from regular federal income tax with a secondary investment objective of capital appreciation. The fund seeks to invest in assets consisting primarily of municipal securities, the interest on which is exempt from regular Federal income tax and preferred securities that are eligible to pay dividends which qualify for the long-term capital gains rate for individual investors.

As of Jan. 27, 2012, MHI's portfolio consisted of approximately 99% municipal securities and 1% among cash, common stock, and corporate bonds. The municipal portion of the portfolio included exposure to the health care (25%), general obligation and lease/apportionment (21%), higher education (19%), corporate backed (15%) and pre-refunded/escrowed (8%) sectors. As of the same date, the fund's top exposures, by state, were Texas (13%), New York (10%), Illinois (9%) and California (9%).

PIONEER MUNICIPAL HIGH INCOME ADVANTAGE TRUST (MAV)

MAV is a diversified closed-end management company, registered under the Investment Company Act of 1940, as amended, that commenced operations in October 2003. The fund seeks to provide a high level of current income exempt from regular Federal income tax with a secondary investment objective of capital appreciation. The fund seeks to invest in assets consisting primarily of municipal securities, the interest on which is exempt from regular Federal income tax and preferred securities that are eligible to pay dividends which qualify for the long-term capital gains rate for individual investors.

As of Jan. 27, 2012, MAV's portfolio consisted of approximately 80% municipal securities and 20% among cash, common stock, and corporate bonds. The municipal portion of the portfolio included exposure to the health care (27%), corporate backed (20%), general obligation and lease/apportionment (13%), higher education (10%), and transportation (9%) municipal sectors. Any amounts over the Fitch municipal sector guideline of 25% are discounted with an additional 10% haircut when calculating the Fitch OC tests. As of the same date, the fund's top exposures, by state, were California (17%), New Jersey (9%), Texas (8%) and New York (6%).

THE ADVISOR

Pioneer acts as the funds' investment advisor and is a wholly owned subsidiary of Pioneer Global Asset Management S.p.A., an investment management arm of UniCredit Banking Group. As of Dec. 31, 2011, Pioneer Global Asset Management S.p.A. had approximately $210 billion of assets under management.

RATINGS SENSITIVITY

The assigned ratings may be sensitive to material changes in the leverage composition, portfolio credit quality or market risk of the fund. A material adverse deviation from Fitch guidelines for any key rating driver could cause the rating to be lowered by Fitch.

For additional information about Fitch's rating guidelines applicable to debt and preferred stock issued by closed-end funds, please review the criteria referenced below, which can be found on Fitch's web site at 'www.fitchratings.com'.

The sources of information used to assess these ratings were the public domain, and Pioneer Investments.

Applicable Criteria and Related Research:

--'Rating Closed-End Fund Debt and Preferred Stock' (Aug. 16, 2011);

--'Global Rating Criteria for Asset-Backed Commercial Paper' (Nov. 10, 2011);

--'2012 Outlook: Closed-End Fund Leverage' (Dec. 19, 2011);

--'Closed-End Funds: Derivatives Under Review' (Nov. 16, 2011);

--'Primer: CEF Variable-Rate Demand Preferred Shares' (Oct. 27, 2011).

Applicable Criteria and Related Research:

Primer: CEF Variable-Rate Demand Preferred Shares (Closed-End Fund VRDPs Target Short-Term, Money Market Investors)

http://www.fitchratings.com/creditdesk/reports/report_frame.cfm?rpt_id=654295

Closed-End Funds: Derivatives Under Review (Increased Use and Limited Transparency Are Key Considerations)

http://www.fitchratings.com/creditdesk/reports/report_frame.cfm?rpt_id=656591

2012 Outlook: Closed-End Fund Leverage

http://www.fitchratings.com/creditdesk/reports/report_frame.cfm?rpt_id=660709

Global Rating Criteria for Asset-Backed Commercial Paper

http://www.fitchratings.com/creditdesk/reports/report_frame.cfm?rpt_id=655450

Rating Closed-End Fund Debt and Preferred Stock

http://www.fitchratings.com/creditdesk/reports/report_frame.cfm?rpt_id=648840

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